---
_id: '14516'
abstract:
- lang: eng
text: 'We revisit decentralized random beacons with a focus on practical distributed
applications. Decentralized random beacons (Beaver and So, Eurocrypt''93) provide
the functionality for n parties to generate an unpredictable sequence of bits
in a way that cannot be biased, which is useful for any decentralized protocol
requiring trusted randomness. Existing beacon constructions are highly inefficient
in practical settings where protocol parties need to rejoin after crashes or disconnections,
and more significantly where smart contracts may rely on arbitrary index points
in high-volume streams. For this, we introduce a new notion of history-generating
decentralized random beacons (HGDRBs). Roughly, the history-generation property
of HGDRBs allows for previous beacon outputs to be efficiently generated knowing
only the current value and the public key. At application layers, history-generation
supports registering a sparser set of on-chain values if desired, so that apps
like lotteries can utilize on-chain values without incurring high-frequency costs,
enjoying all the benefits of DRBs implemented off-chain or with decoupled, special-purpose
chains. Unlike rollups, HG is tailored specifically to recovering and verifying
pseudorandom bit sequences and thus enjoys unique optimizations investigated in
this work. We introduce STROBE: an efficient HGDRB construction which generalizes
the original squaring-based RSA approach of Beaver and So. STROBE enjoys several
useful properties that make it suited for practical applications that use beacons:
1) history-generating: it can regenerate and verify high-throughput beacon streams,
supporting sparse (thus cost-effective) ledger entries; 2) concisely self-verifying:
NIZK-free, with state and validation employing a single ring element; 3) eco-friendly:
stake-based rather than work based; 4) unbounded: refresh-free, addressing limitations
of Beaver and So; 5) delay-free: results are immediately available. 6) storage-efficient:
the last beacon suffices to derive all past outputs, thus O(1) storage requirements
for nodes serving the whole history.'
acknowledgement: Work done when all the authors were at Novi Research, Meta.
alternative_title:
- LIPIcs
article_number: '7'
article_processing_charge: Yes
author:
- first_name: Donald
full_name: Beaver, Donald
last_name: Beaver
- first_name: Mahimna
full_name: Kelkar, Mahimna
last_name: Kelkar
- first_name: Kevin
full_name: Lewi, Kevin
last_name: Lewi
- first_name: Valeria
full_name: Nikolaenko, Valeria
last_name: Nikolaenko
- first_name: Alberto
full_name: Sonnino, Alberto
last_name: Sonnino
- first_name: Konstantinos
full_name: Chalkias, Konstantinos
last_name: Chalkias
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Ladi De
full_name: Naurois, Ladi De
last_name: Naurois
- first_name: Arnab
full_name: Roy, Arnab
last_name: Roy
citation:
ama: 'Beaver D, Kelkar M, Lewi K, et al. STROBE: Streaming Threshold Random Beacons.
In: 5th Conference on Advances in Financial Technologies. Vol 282. Schloss
Dagstuhl - Leibniz-Zentrum für Informatik; 2023. doi:10.4230/LIPIcs.AFT.2023.7'
apa: 'Beaver, D., Kelkar, M., Lewi, K., Nikolaenko, V., Sonnino, A., Chalkias, K.,
… Roy, A. (2023). STROBE: Streaming Threshold Random Beacons. In 5th Conference
on Advances in Financial Technologies (Vol. 282). Princeton, NJ, United States:
Schloss Dagstuhl - Leibniz-Zentrum für Informatik. https://doi.org/10.4230/LIPIcs.AFT.2023.7'
chicago: 'Beaver, Donald, Mahimna Kelkar, Kevin Lewi, Valeria Nikolaenko, Alberto
Sonnino, Konstantinos Chalkias, Eleftherios Kokoris Kogias, Ladi De Naurois, and
Arnab Roy. “STROBE: Streaming Threshold Random Beacons.” In 5th Conference
on Advances in Financial Technologies, Vol. 282. Schloss Dagstuhl - Leibniz-Zentrum
für Informatik, 2023. https://doi.org/10.4230/LIPIcs.AFT.2023.7.'
ieee: 'D. Beaver et al., “STROBE: Streaming Threshold Random Beacons,” in
5th Conference on Advances in Financial Technologies, Princeton, NJ, United
States, 2023, vol. 282.'
ista: 'Beaver D, Kelkar M, Lewi K, Nikolaenko V, Sonnino A, Chalkias K, Kokoris
Kogias E, Naurois LD, Roy A. 2023. STROBE: Streaming Threshold Random Beacons.
5th Conference on Advances in Financial Technologies. AFT: Conference on Advances
in Financial Technologies, LIPIcs, vol. 282, 7.'
mla: 'Beaver, Donald, et al. “STROBE: Streaming Threshold Random Beacons.” 5th
Conference on Advances in Financial Technologies, vol. 282, 7, Schloss Dagstuhl
- Leibniz-Zentrum für Informatik, 2023, doi:10.4230/LIPIcs.AFT.2023.7.'
short: D. Beaver, M. Kelkar, K. Lewi, V. Nikolaenko, A. Sonnino, K. Chalkias, E.
Kokoris Kogias, L.D. Naurois, A. Roy, in:, 5th Conference on Advances in Financial
Technologies, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023.
conference:
end_date: 2023-10-25
location: Princeton, NJ, United States
name: 'AFT: Conference on Advances in Financial Technologies'
start_date: 2023-10-23
date_created: 2023-11-12T23:00:55Z
date_published: 2023-10-01T00:00:00Z
date_updated: 2023-11-13T08:52:01Z
day: '01'
ddc:
- '000'
department:
- _id: ElKo
doi: 10.4230/LIPIcs.AFT.2023.7
file:
- access_level: open_access
checksum: c1f98831cb5149d6c030c41999e6e960
content_type: application/pdf
creator: dernst
date_created: 2023-11-13T08:44:34Z
date_updated: 2023-11-13T08:44:34Z
file_id: '14521'
file_name: 2023_LIPIcs_Beaver.pdf
file_size: 793495
relation: main_file
success: 1
file_date_updated: 2023-11-13T08:44:34Z
has_accepted_license: '1'
intvolume: ' 282'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2021/1643
month: '10'
oa: 1
oa_version: Published Version
publication: 5th Conference on Advances in Financial Technologies
publication_identifier:
isbn:
- '9783959773034'
issn:
- 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'STROBE: Streaming Threshold Random Beacons'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 282
year: '2023'
...
---
_id: '14609'
abstract:
- lang: eng
text: "Distributed Key Generation (DKG) is a technique to bootstrap threshold cryptosystems
without a trusted party. DKG is an essential building block to many decentralized
protocols such as randomness beacons, threshold signatures, Byzantine consensus,
and multiparty computation. While significant progress has been made recently,
existing asynchronous DKG constructions are inefficient when the reconstruction
threshold is larger than one-third of the total nodes. In this paper, we present
a simple and concretely efficient asynchronous DKG (ADKG) protocol among n = 3t
+ 1 nodes that can tolerate up to t malicious nodes and support any reconstruction
threshold ℓ ≥ t. Our protocol has an expected O(κn3) communication cost, where
κ is the security parameter, and only assumes the hardness of the Discrete Logarithm.
The\r\ncore ingredient of our ADKG protocol is an asynchronous protocol to secret
share a random polynomial of degree ℓ ≥ t, which has other applications, such
as asynchronous proactive secret sharing and asynchronous multiparty computation.
We implement our high-threshold ADKG protocol and evaluate it using a network
of up to 128 geographically distributed nodes. Our evaluation shows that our high-threshold
ADKG protocol reduces the running time by 90% and bandwidth usage by 80% over
the state-of-the-art."
acknowledgement: The authors would like to thank Amit Agarwal, Andrew Miller, and
Tom Yurek for the helpful discussions related to the paper. This work is funded
in part by a VMware early career faculty grant, a Chainlink Labs Ph.D. fellowship,
the National Science Foundation, and the Austrian Science Fund (FWF) F8512-N.
article_processing_charge: No
author:
- first_name: Sourav
full_name: Das, Sourav
last_name: Das
- first_name: Zhuolun
full_name: Xiang, Zhuolun
last_name: Xiang
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Ling
full_name: Ren, Ling
last_name: Ren
citation:
ama: 'Das S, Xiang Z, Kokoris Kogias E, Ren L. Practical asynchronous high-threshold
distributed key generation and distributed polynomial sampling. In: 32nd USENIX
Security Symposium. Vol 8. Usenix; 2023:5359-5376.'
apa: 'Das, S., Xiang, Z., Kokoris Kogias, E., & Ren, L. (2023). Practical asynchronous
high-threshold distributed key generation and distributed polynomial sampling.
In 32nd USENIX Security Symposium (Vol. 8, pp. 5359–5376). Anaheim, CA,
United States: Usenix.'
chicago: Das, Sourav, Zhuolun Xiang, Eleftherios Kokoris Kogias, and Ling Ren. “Practical
Asynchronous High-Threshold Distributed Key Generation and Distributed Polynomial
Sampling.” In 32nd USENIX Security Symposium, 8:5359–76. Usenix, 2023.
ieee: S. Das, Z. Xiang, E. Kokoris Kogias, and L. Ren, “Practical asynchronous high-threshold
distributed key generation and distributed polynomial sampling,” in 32nd USENIX
Security Symposium, Anaheim, CA, United States, 2023, vol. 8, pp. 5359–5376.
ista: Das S, Xiang Z, Kokoris Kogias E, Ren L. 2023. Practical asynchronous high-threshold
distributed key generation and distributed polynomial sampling. 32nd USENIX Security
Symposium. USENIX Security Symposium vol. 8, 5359–5376.
mla: Das, Sourav, et al. “Practical Asynchronous High-Threshold Distributed Key
Generation and Distributed Polynomial Sampling.” 32nd USENIX Security Symposium,
vol. 8, Usenix, 2023, pp. 5359–76.
short: S. Das, Z. Xiang, E. Kokoris Kogias, L. Ren, in:, 32nd USENIX Security Symposium,
Usenix, 2023, pp. 5359–5376.
conference:
end_date: 2023-08-11
location: Anaheim, CA, United States
name: USENIX Security Symposium
start_date: 2023-08-09
date_created: 2023-11-26T23:00:55Z
date_published: 2023-08-15T00:00:00Z
date_updated: 2023-11-28T09:17:38Z
day: '15'
ddc:
- '000'
department:
- _id: ElKo
file:
- access_level: open_access
checksum: 1a730765930138e23c6efd2575872641
content_type: application/pdf
creator: dernst
date_created: 2023-11-28T09:14:34Z
date_updated: 2023-11-28T09:14:34Z
file_id: '14621'
file_name: 2023_USENIX_Das.pdf
file_size: 704331
relation: main_file
success: 1
file_date_updated: 2023-11-28T09:14:34Z
has_accepted_license: '1'
intvolume: ' 8'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2022/1389
month: '08'
oa: 1
oa_version: Published Version
page: 5359-5376
project:
- _id: 34a4ce89-11ca-11ed-8bc3-8cc37fb6e11f
grant_number: F8512
name: Secure Network and Hardware for Efficient Blockchains
publication: 32nd USENIX Security Symposium
publication_identifier:
isbn:
- '9781713879497'
publication_status: published
publisher: Usenix
quality_controlled: '1'
scopus_import: '1'
status: public
title: Practical asynchronous high-threshold distributed key generation and distributed
polynomial sampling
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 8
year: '2023'
...
---
_id: '14735'
abstract:
- lang: eng
text: "Scaling blockchain protocols to perform on par with the expected needs of
Web3.0 has been proven to be a challenging task with almost a decade of research.
In the forefront of the current solution is the idea of separating the execution
of the updates encoded in a block from the ordering of blocks. In order to achieve
this, a new class of protocols called rollups has emerged. Rollups have as input
a total ordering of valid and invalid transactions and as output a new valid state-transition.\r\nIf
we study rollups from a distributed computing perspective, we uncover that rollups
take as input the output of a Byzantine Atomic Broadcast (BAB) protocol and convert
it to a State Machine Replication (SMR) protocol. BAB and SMR, however, are considered
equivalent as far as distributed computing is concerned and a solution to one
can easily be retrofitted to solve the other simply by adding/removing an execution
step before the validation of the input.\r\nThis “easy” step of retrofitting an
atomic broadcast solution to implement an SMR has, however, been overlooked in
practice. In this paper, we formalize the problem and show that after BAB is solved,
traditional impossibility results for consensus no longer apply towards an SMR.
Leveraging this we propose a distributed execution protocol that allows reduced
execution and storage cost per executor (O(log2n/n)) without relaxing the network
assumptions of the underlying BAB protocol and providing censorship-resistance.
Finally, we propose efficient non-interactive light client constructions that
leverage our efficient execution protocols and do not require any synchrony assumptions
or expensive ZK-proofs."
acknowledgement: 'Eleftherios Kokoris-Kogias is partially supported by Austrian Science
Fund (FWF) grant No: F8512-N.'
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Christos
full_name: Stefo, Christos
id: a20e8902-32b0-11ee-9fa8-b23fa638b793
last_name: Stefo
- first_name: Zhuolun
full_name: Xiang, Zhuolun
last_name: Xiang
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
citation:
ama: 'Stefo C, Xiang Z, Kokoris Kogias E. Executing and proving over dirty ledgers.
In: 27th International Conference on Financial Cryptography and Data Security.
Vol 13950. Springer Nature; 2023:3-20. doi:10.1007/978-3-031-47754-6_1'
apa: 'Stefo, C., Xiang, Z., & Kokoris Kogias, E. (2023). Executing and proving
over dirty ledgers. In 27th International Conference on Financial Cryptography
and Data Security (Vol. 13950, pp. 3–20). Bol, Brac, Croatia: Springer Nature.
https://doi.org/10.1007/978-3-031-47754-6_1'
chicago: Stefo, Christos, Zhuolun Xiang, and Eleftherios Kokoris Kogias. “Executing
and Proving over Dirty Ledgers.” In 27th International Conference on Financial
Cryptography and Data Security, 13950:3–20. Springer Nature, 2023. https://doi.org/10.1007/978-3-031-47754-6_1.
ieee: C. Stefo, Z. Xiang, and E. Kokoris Kogias, “Executing and proving over dirty
ledgers,” in 27th International Conference on Financial Cryptography and Data
Security, Bol, Brac, Croatia, 2023, vol. 13950, pp. 3–20.
ista: 'Stefo C, Xiang Z, Kokoris Kogias E. 2023. Executing and proving over dirty
ledgers. 27th International Conference on Financial Cryptography and Data Security.
FC: Financial Cryptography and Data Security, LNCS, vol. 13950, 3–20.'
mla: Stefo, Christos, et al. “Executing and Proving over Dirty Ledgers.” 27th
International Conference on Financial Cryptography and Data Security, vol.
13950, Springer Nature, 2023, pp. 3–20, doi:10.1007/978-3-031-47754-6_1.
short: C. Stefo, Z. Xiang, E. Kokoris Kogias, in:, 27th International Conference
on Financial Cryptography and Data Security, Springer Nature, 2023, pp. 3–20.
conference:
end_date: 2023-05-05
location: Bol, Brac, Croatia
name: 'FC: Financial Cryptography and Data Security'
start_date: 2023-05-01
date_created: 2024-01-08T09:17:38Z
date_published: 2023-12-01T00:00:00Z
date_updated: 2024-01-08T09:28:14Z
day: '01'
department:
- _id: ElKo
- _id: GradSch
doi: 10.1007/978-3-031-47754-6_1
intvolume: ' 13950'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2022/1554
month: '12'
oa: 1
oa_version: Preprint
page: 3-20
project:
- _id: 34a4ce89-11ca-11ed-8bc3-8cc37fb6e11f
grant_number: F8512
name: Secure Network and Hardware for Efficient Blockchains
publication: 27th International Conference on Financial Cryptography and Data Security
publication_identifier:
eisbn:
- '9783031477546'
eissn:
- 0302-9743
isbn:
- '9783031477539'
issn:
- 1611-3349
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Executing and proving over dirty ledgers
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 13950
year: '2023'
...
---
_id: '14744'
abstract:
- lang: eng
text: "Sharding distributed ledgers is a promising on-chain solution for scaling
blockchains but lacks formal grounds, nurturing skepticism on whether such complex
systems can scale blockchains securely. We fill this gap by introducing the first
formal framework as well as a roadmap to robust sharding. In particular, we first
define the properties sharded distributed ledgers should fulfill. We build upon
and extend the Bitcoin backbone protocol by defining consistency and scalability.
Consistency encompasses the need for atomic execution of cross-shard transactions
to preserve safety, whereas scalability encapsulates the speedup a sharded system
can gain in comparison to a non-sharded system.\r\nUsing our model, we explore
the limitations of sharding. We show that a sharded ledger with n participants
cannot scale under a fully adaptive adversary, but it can scale up to m shards
where n=c'm log m, under an epoch-adaptive adversary; the constant c' encompasses
the trade-off between security and scalability. This is possible only if the sharded
ledgers create succinct proofs of the valid state updates at every epoch. We leverage
our results to identify the sufficient components for robust sharding, which we
incorporate in a protocol abstraction termed Divide & Scale. To demonstrate the
power of our framework, we analyze the most prominent sharded blockchains (Elastico,
Monoxide, OmniLedger, RapidChain) and pinpoint where they fail to meet the desired
properties."
acknowledgement: The work was partially supported by the Austrian Science Fund (FWF)
through the project CoRaF (grant agreement 2020388).
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Zeta
full_name: Avarikioti, Zeta
last_name: Avarikioti
- first_name: Antoine
full_name: Desjardins, Antoine
id: 06d0c166-aec1-11ee-a7c0-b96e840a602b
last_name: Desjardins
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Roger
full_name: Wattenhofer, Roger
last_name: Wattenhofer
citation:
ama: 'Avarikioti Z, Desjardins A, Kokoris Kogias E, Wattenhofer R. Divide &
Scale: Formalization and roadmap to robust sharding. In: 30th International
Colloquium on Structural Information and Communication Complexity. Vol 13892.
Springer Nature; 2023:199-245. doi:10.1007/978-3-031-32733-9_10'
apa: 'Avarikioti, Z., Desjardins, A., Kokoris Kogias, E., & Wattenhofer, R.
(2023). Divide & Scale: Formalization and roadmap to robust sharding. In 30th
International Colloquium on Structural Information and Communication Complexity
(Vol. 13892, pp. 199–245). Alcalá de Henares, Spain: Springer Nature. https://doi.org/10.1007/978-3-031-32733-9_10'
chicago: 'Avarikioti, Zeta, Antoine Desjardins, Eleftherios Kokoris Kogias, and
Roger Wattenhofer. “Divide & Scale: Formalization and Roadmap to Robust Sharding.”
In 30th International Colloquium on Structural Information and Communication
Complexity, 13892:199–245. Springer Nature, 2023. https://doi.org/10.1007/978-3-031-32733-9_10.'
ieee: 'Z. Avarikioti, A. Desjardins, E. Kokoris Kogias, and R. Wattenhofer, “Divide
& Scale: Formalization and roadmap to robust sharding,” in 30th International
Colloquium on Structural Information and Communication Complexity, Alcalá
de Henares, Spain, 2023, vol. 13892, pp. 199–245.'
ista: 'Avarikioti Z, Desjardins A, Kokoris Kogias E, Wattenhofer R. 2023. Divide
& Scale: Formalization and roadmap to robust sharding. 30th International
Colloquium on Structural Information and Communication Complexity. SIROCCO: Structural
Information and Communication Complexity, LNCS, vol. 13892, 199–245.'
mla: 'Avarikioti, Zeta, et al. “Divide & Scale: Formalization and Roadmap to Robust
Sharding.” 30th International Colloquium on Structural Information and Communication
Complexity, vol. 13892, Springer Nature, 2023, pp. 199–245, doi:10.1007/978-3-031-32733-9_10.'
short: Z. Avarikioti, A. Desjardins, E. Kokoris Kogias, R. Wattenhofer, in:, 30th
International Colloquium on Structural Information and Communication Complexity,
Springer Nature, 2023, pp. 199–245.
conference:
end_date: 2023-06-09
location: Alcalá de Henares, Spain
name: 'SIROCCO: Structural Information and Communication Complexity'
start_date: 2023-06-06
date_created: 2024-01-08T12:56:46Z
date_published: 2023-06-01T00:00:00Z
date_updated: 2024-01-09T07:40:57Z
day: '01'
department:
- _id: ElKo
doi: 10.1007/978-3-031-32733-9_10
intvolume: ' 13892'
language:
- iso: eng
month: '06'
oa_version: None
page: 199-245
publication: 30th International Colloquium on Structural Information and Communication
Complexity
publication_identifier:
eisbn:
- '9783031327339'
eissn:
- 1611-3349
isbn:
- '9783031327322'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Divide & Scale: Formalization and roadmap to robust sharding'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 13892
year: '2023'
...
---
_id: '14829'
abstract:
- lang: eng
text: 'This paper explores a modular design architecture aimed at helping blockchains
(and other SMR implementation) to scale to a very large number of processes. This
comes in contrast to existing monolithic architectures that interleave transaction
dissemination, ordering, and execution in a single functionality. To achieve this
we first split the monolith to multiple layers which can use existing distributed
computing primitives. The exact specifications of the data dissemination part
are formally defined by the Proof of Availability & Retrieval (PoA &R) abstraction.
Solutions to the PoA &R problem contain two related sub-protocols: one that “pushes”
information into the network and another that “pulls” this information. Regarding
the latter, there is a dearth of research literature which is rectified in this
paper. We present a family of pulling sub-protocols and rigorously analyze them.
Extensive simulations support the theoretical claims of efficiency and robustness
in case of a very large number of players. Finally, actual implementation and
deployment on a small number of machines (roughly the size of several industrial
systems) demonstrates the viability of the architecture’s paradigm.'
acknowledgement: 'This work is partially supported by Meta. Eleftherios Kokoris-Kogias
is partially supported by Austrian Science Fund (FWF) grant No: F8512-N. Shir Cohen
is supported by the Adams Fellowship Program of the Israel Academy of Sciences and
Humanities.'
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Shir
full_name: Cohen, Shir
last_name: Cohen
- first_name: Guy
full_name: Goren, Guy
last_name: Goren
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Alberto
full_name: Sonnino, Alberto
last_name: Sonnino
- first_name: Alexander
full_name: Spiegelman, Alexander
last_name: Spiegelman
citation:
ama: 'Cohen S, Goren G, Kokoris Kogias E, Sonnino A, Spiegelman A. Proof of availability
and retrieval in a modular blockchain architecture. In: 27th International
Conference on Financial Cryptography and Data Security. Vol 13951. Springer
Nature; 2023:36-53. doi:10.1007/978-3-031-47751-5_3'
apa: 'Cohen, S., Goren, G., Kokoris Kogias, E., Sonnino, A., & Spiegelman, A.
(2023). Proof of availability and retrieval in a modular blockchain architecture.
In 27th International Conference on Financial Cryptography and Data Security
(Vol. 13951, pp. 36–53). Bol, Brac, Croatia: Springer Nature. https://doi.org/10.1007/978-3-031-47751-5_3'
chicago: Cohen, Shir, Guy Goren, Eleftherios Kokoris Kogias, Alberto Sonnino, and
Alexander Spiegelman. “Proof of Availability and Retrieval in a Modular Blockchain
Architecture.” In 27th International Conference on Financial Cryptography and
Data Security, 13951:36–53. Springer Nature, 2023. https://doi.org/10.1007/978-3-031-47751-5_3.
ieee: S. Cohen, G. Goren, E. Kokoris Kogias, A. Sonnino, and A. Spiegelman, “Proof
of availability and retrieval in a modular blockchain architecture,” in 27th
International Conference on Financial Cryptography and Data Security, Bol,
Brac, Croatia, 2023, vol. 13951, pp. 36–53.
ista: 'Cohen S, Goren G, Kokoris Kogias E, Sonnino A, Spiegelman A. 2023. Proof
of availability and retrieval in a modular blockchain architecture. 27th International
Conference on Financial Cryptography and Data Security. FC: Financial Cryptography
and Data Security, LNCS, vol. 13951, 36–53.'
mla: Cohen, Shir, et al. “Proof of Availability and Retrieval in a Modular Blockchain
Architecture.” 27th International Conference on Financial Cryptography and
Data Security, vol. 13951, Springer Nature, 2023, pp. 36–53, doi:10.1007/978-3-031-47751-5_3.
short: S. Cohen, G. Goren, E. Kokoris Kogias, A. Sonnino, A. Spiegelman, in:, 27th
International Conference on Financial Cryptography and Data Security, Springer
Nature, 2023, pp. 36–53.
conference:
end_date: 2023-05-05
location: Bol, Brac, Croatia
name: 'FC: Financial Cryptography and Data Security'
start_date: 2023-05-01
date_created: 2024-01-18T07:41:12Z
date_published: 2023-12-01T00:00:00Z
date_updated: 2024-01-22T13:58:07Z
day: '01'
department:
- _id: ElKo
doi: 10.1007/978-3-031-47751-5_3
intvolume: ' 13951'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://fc23.ifca.ai/preproceedings/150.pdf
month: '12'
oa: 1
oa_version: Submitted Version
page: 36-53
project:
- _id: 34a4ce89-11ca-11ed-8bc3-8cc37fb6e11f
grant_number: F8512
name: Secure Network and Hardware for Efficient Blockchains
publication: 27th International Conference on Financial Cryptography and Data Security
publication_identifier:
eisbn:
- '9783031477515'
eissn:
- 1611-3349
isbn:
- '9783031477508'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Proof of availability and retrieval in a modular blockchain architecture
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 13951
year: '2023'
...
---
_id: '14989'
abstract:
- lang: eng
text: "Encryption alone is not enough for secure end-to end encrypted messaging:
a server must also honestly serve public keys to users. Key transparency has been
presented as an efficient\r\nsolution for detecting (and hence deterring) a server
that attempts to dishonestly serve keys. Key transparency involves two major components:
(1) a username to public key mapping, stored and cryptographically committed to
by the server, and, (2) an outof-band consistency protocol for serving short commitments
to users. In the setting of real-world deployments and supporting production scale,
new challenges must be considered for both of these components. We enumerate these
challenges and provide solutions to address them. In particular, we design and
implement a memory-optimized and privacy-preserving verifiable data structure
for committing to the username to public key store.\r\nTo make this implementation
viable for production, we also integrate support for persistent and distributed
storage. We also propose a future-facing solution, termed “compaction”, as\r\na
mechanism for mitigating practical issues that arise from dealing with infinitely
growing server data structures. Finally, we implement a consensusless solution
that achieves the minimum requirements for a service that consistently distributes
commitments for a transparency application, providing a much more efficient protocol
for distributing small and consistent\r\ncommitments to users. This culminates
in our production-grade implementation of a key transparency system (Parakeet)
which we have open-sourced, along with a demonstration of feasibility through
our benchmarks."
acknowledgement: This work is supported by the Novi team at Meta and funded in part
by IC3 industry partners and NSF grant 1943499.
article_processing_charge: No
author:
- first_name: Harjasleen
full_name: Malvai, Harjasleen
last_name: Malvai
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Alberto
full_name: Sonnino, Alberto
last_name: Sonnino
- first_name: Esha
full_name: Ghosh, Esha
last_name: Ghosh
- first_name: Ercan
full_name: Oztürk, Ercan
last_name: Oztürk
- first_name: Kevin
full_name: Lewi, Kevin
last_name: Lewi
- first_name: Sean
full_name: Lawlor, Sean
last_name: Lawlor
citation:
ama: 'Malvai H, Kokoris Kogias E, Sonnino A, et al. Parakeet: Practical key transparency
for end-to-end eEncrypted messaging. In: Proceedings of the 2023 Network and
Distributed System Security Symposium. Internet Society; 2023. doi:10.14722/ndss.2023.24545'
apa: 'Malvai, H., Kokoris Kogias, E., Sonnino, A., Ghosh, E., Oztürk, E., Lewi,
K., & Lawlor, S. (2023). Parakeet: Practical key transparency for end-to-end
eEncrypted messaging. In Proceedings of the 2023 Network and Distributed System
Security Symposium. San Diego, CA, United States: Internet Society. https://doi.org/10.14722/ndss.2023.24545'
chicago: 'Malvai, Harjasleen, Eleftherios Kokoris Kogias, Alberto Sonnino, Esha
Ghosh, Ercan Oztürk, Kevin Lewi, and Sean Lawlor. “Parakeet: Practical Key Transparency
for End-to-End EEncrypted Messaging.” In Proceedings of the 2023 Network and
Distributed System Security Symposium. Internet Society, 2023. https://doi.org/10.14722/ndss.2023.24545.'
ieee: 'H. Malvai et al., “Parakeet: Practical key transparency for end-to-end
eEncrypted messaging,” in Proceedings of the 2023 Network and Distributed System
Security Symposium, San Diego, CA, United States, 2023.'
ista: 'Malvai H, Kokoris Kogias E, Sonnino A, Ghosh E, Oztürk E, Lewi K, Lawlor
S. 2023. Parakeet: Practical key transparency for end-to-end eEncrypted messaging.
Proceedings of the 2023 Network and Distributed System Security Symposium. NDSS:
Network and Distributed Systems Security.'
mla: 'Malvai, Harjasleen, et al. “Parakeet: Practical Key Transparency for End-to-End
EEncrypted Messaging.” Proceedings of the 2023 Network and Distributed System
Security Symposium, Internet Society, 2023, doi:10.14722/ndss.2023.24545.'
short: H. Malvai, E. Kokoris Kogias, A. Sonnino, E. Ghosh, E. Oztürk, K. Lewi, S.
Lawlor, in:, Proceedings of the 2023 Network and Distributed System Security Symposium,
Internet Society, 2023.
conference:
end_date: 2023-03-03
location: San Diego, CA, United States
name: 'NDSS: Network and Distributed Systems Security'
start_date: 2023-02-27
date_created: 2024-02-14T14:20:40Z
date_published: 2023-03-01T00:00:00Z
date_updated: 2024-02-19T12:11:15Z
day: '01'
department:
- _id: ElKo
doi: 10.14722/ndss.2023.24545
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2023/081
month: '03'
oa: 1
oa_version: Published Version
publication: Proceedings of the 2023 Network and Distributed System Security Symposium
publication_identifier:
isbn:
- '1891562835'
publication_status: published
publisher: Internet Society
quality_controlled: '1'
status: public
title: 'Parakeet: Practical key transparency for end-to-end eEncrypted messaging'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2023'
...
---
_id: '14743'
abstract:
- lang: eng
text: Leader-based consensus algorithms are fast and efficient under normal conditions,
but lack robustness to adverse conditions due to their reliance on timeouts for
liveness. We present QuePaxa, the first protocol offering state-of-the-art normal-case
efficiency without depending on timeouts. QuePaxa uses a novel randomized asynchronous
consensus core to tolerate adverse conditions such as denial-of-service (DoS)
attacks, while a one-round-trip fast path preserves the normal-case efficiency
of Multi-Paxos or Raft. By allowing simultaneous proposers without destructive
interference, and using short hedging delays instead of conservative timeouts
to limit redundant effort, QuePaxa permits rapid recovery after leader failure
without risking costly view changes due to false timeouts. By treating leader
choice and hedging delay as a multi-armed-bandit optimization, QuePaxa achieves
responsiveness to prevalent conditions, and can choose the best leader even if
the current one has not failed. Experiments with a prototype confirm that QuePaxa
achieves normal-case LAN and WAN performance of 584k and 250k cmd/sec in throughput,
respectively, comparable to Multi-Paxos. Under conditions such as DoS attacks,
misconfigurations, or slow leaders that severely impact existing protocols, we
find that QuePaxa remains live with median latency under 380ms in WAN experiments.
acknowledgement: The authors would like to thank Marcos K. Aguilera, Pierluca Borsò,
Aleksey Charapko, Rachid Guerraoui, Jovan Komatovic, Derek Leung, Louis-Henri Merino,
Shailesh Mishra, Haochen Pan, Rodrigo Rodrigues, Lewis Tseng, and Haoqian Zhang
for their helpful feedback on early drafts of this paper.
article_processing_charge: No
author:
- first_name: Pasindu
full_name: Tennage, Pasindu
last_name: Tennage
- first_name: Cristina
full_name: Basescu, Cristina
last_name: Basescu
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Ewa
full_name: Syta, Ewa
last_name: Syta
- first_name: Philipp
full_name: Jovanovic, Philipp
last_name: Jovanovic
- first_name: Vero
full_name: Estrada-Galinanes, Vero
last_name: Estrada-Galinanes
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
citation:
ama: 'Tennage P, Basescu C, Kokoris Kogias E, et al. QuePaxa: Escaping the tyranny
of timeouts in consensus. In: Proceedings of the 29th Symposium on Operating
Systems Principles. Association for Computing Machinery; 2023:281-297. doi:10.1145/3600006.3613150'
apa: 'Tennage, P., Basescu, C., Kokoris Kogias, E., Syta, E., Jovanovic, P., Estrada-Galinanes,
V., & Ford, B. (2023). QuePaxa: Escaping the tyranny of timeouts in consensus.
In Proceedings of the 29th Symposium on Operating Systems Principles (pp.
281–297). Koblenz, Germany: Association for Computing Machinery. https://doi.org/10.1145/3600006.3613150'
chicago: 'Tennage, Pasindu, Cristina Basescu, Eleftherios Kokoris Kogias, Ewa Syta,
Philipp Jovanovic, Vero Estrada-Galinanes, and Bryan Ford. “QuePaxa: Escaping
the Tyranny of Timeouts in Consensus.” In Proceedings of the 29th Symposium
on Operating Systems Principles, 281–97. Association for Computing Machinery,
2023. https://doi.org/10.1145/3600006.3613150.'
ieee: 'P. Tennage et al., “QuePaxa: Escaping the tyranny of timeouts in consensus,”
in Proceedings of the 29th Symposium on Operating Systems Principles, Koblenz,
Germany, 2023, pp. 281–297.'
ista: 'Tennage P, Basescu C, Kokoris Kogias E, Syta E, Jovanovic P, Estrada-Galinanes
V, Ford B. 2023. QuePaxa: Escaping the tyranny of timeouts in consensus. Proceedings
of the 29th Symposium on Operating Systems Principles. SOSP: Symposium on Operating
Systems Principles, 281–297.'
mla: 'Tennage, Pasindu, et al. “QuePaxa: Escaping the Tyranny of Timeouts in Consensus.”
Proceedings of the 29th Symposium on Operating Systems Principles, Association
for Computing Machinery, 2023, pp. 281–97, doi:10.1145/3600006.3613150.'
short: P. Tennage, C. Basescu, E. Kokoris Kogias, E. Syta, P. Jovanovic, V. Estrada-Galinanes,
B. Ford, in:, Proceedings of the 29th Symposium on Operating Systems Principles,
Association for Computing Machinery, 2023, pp. 281–297.
conference:
end_date: 2023-10-26
location: Koblenz, Germany
name: 'SOSP: Symposium on Operating Systems Principles'
start_date: 2023-10-23
date_created: 2024-01-08T12:54:35Z
date_published: 2023-10-01T00:00:00Z
date_updated: 2024-02-28T12:51:24Z
day: '01'
department:
- _id: ElKo
doi: 10.1145/3600006.3613150
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1145/3600006.3613150
month: '10'
oa: 1
oa_version: Published Version
page: 281-297
publication: Proceedings of the 29th Symposium on Operating Systems Principles
publication_identifier:
isbn:
- '9798400702297'
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'QuePaxa: Escaping the tyranny of timeouts in consensus'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2023'
...
---
_id: '12229'
abstract:
- lang: eng
text: "We present Bullshark, the first directed acyclic graph (DAG) based asynchronous
Byzantine Atomic Broadcast protocol that is optimized for the common synchronous
case. Like previous DAG-based BFT protocols [19, 25], Bullshark requires no extra
communication to achieve consensus on top of building the DAG. That is, parties
can totally order the vertices of the DAG by interpreting their local view of
the DAG edges. Unlike other asynchronous DAG-based protocols, Bullshark provides
a practical low latency fast-path that exploits synchronous periods and deprecates
the need for notoriously complex view-change and view-synchronization mechanisms.
Bullshark achieves this while maintaining all the desired properties of its predecessor
DAG-Rider [25]. Namely, it has optimal amortized communication complexity, it
provides fairness and asynchronous liveness, and safety is guaranteed even under
a quantum adversary.\r\n\r\nIn order to show the practicality and simplicity of
our approach, we also introduce a standalone partially synchronous version of
Bullshark, which we evaluate against the state of the art. The implemented protocol
is embarrassingly simple (200 LOC on top of an existing DAG-based mempool implementation).
It is highly efficient, achieving for example, 125,000 transactions per second
with a 2 seconds latency for a deployment of 50 parties. In the same setting,
the state of the art pays a steep 50% latency increase as it optimizes for asynchrony."
article_processing_charge: No
author:
- first_name: Alexander
full_name: Spiegelman, Alexander
last_name: Spiegelman
- first_name: Neil
full_name: Giridharan, Neil
last_name: Giridharan
- first_name: Alberto
full_name: Sonnino, Alberto
last_name: Sonnino
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
citation:
ama: 'Spiegelman A, Giridharan N, Sonnino A, Kokoris Kogias E. Bullshark: DAG BFT
protocols made practical. In: Proceedings of the 2022 ACM SIGSAC Conference
on Computer and Communications Security. Association for Computing Machinery;
2022:2705–2718. doi:10.1145/3548606.3559361'
apa: 'Spiegelman, A., Giridharan, N., Sonnino, A., & Kokoris Kogias, E. (2022).
Bullshark: DAG BFT protocols made practical. In Proceedings of the 2022 ACM
SIGSAC Conference on Computer and Communications Security (pp. 2705–2718).
Los Angeles, CA, United States: Association for Computing Machinery. https://doi.org/10.1145/3548606.3559361'
chicago: 'Spiegelman, Alexander, Neil Giridharan, Alberto Sonnino, and Eleftherios
Kokoris Kogias. “Bullshark: DAG BFT Protocols Made Practical.” In Proceedings
of the 2022 ACM SIGSAC Conference on Computer and Communications Security,
2705–2718. Association for Computing Machinery, 2022. https://doi.org/10.1145/3548606.3559361.'
ieee: 'A. Spiegelman, N. Giridharan, A. Sonnino, and E. Kokoris Kogias, “Bullshark:
DAG BFT protocols made practical,” in Proceedings of the 2022 ACM SIGSAC Conference
on Computer and Communications Security, Los Angeles, CA, United States, 2022,
pp. 2705–2718.'
ista: 'Spiegelman A, Giridharan N, Sonnino A, Kokoris Kogias E. 2022. Bullshark:
DAG BFT protocols made practical. Proceedings of the 2022 ACM SIGSAC Conference
on Computer and Communications Security. CCS: CConference on Computer and Communications
Security, 2705–2718.'
mla: 'Spiegelman, Alexander, et al. “Bullshark: DAG BFT Protocols Made Practical.”
Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications
Security, Association for Computing Machinery, 2022, pp. 2705–2718, doi:10.1145/3548606.3559361.'
short: A. Spiegelman, N. Giridharan, A. Sonnino, E. Kokoris Kogias, in:, Proceedings
of the 2022 ACM SIGSAC Conference on Computer and Communications Security, Association
for Computing Machinery, 2022, pp. 2705–2718.
conference:
end_date: 2022-11-11
location: Los Angeles, CA, United States
name: 'CCS: CConference on Computer and Communications Security'
start_date: 2022-11-07
date_created: 2023-01-16T09:49:48Z
date_published: 2022-11-01T00:00:00Z
date_updated: 2023-01-27T10:33:17Z
day: '01'
department:
- _id: ElKo
doi: 10.1145/3548606.3559361
external_id:
arxiv:
- '2201.05677'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.48550/arXiv.2201.05677
month: '11'
oa: 1
oa_version: Preprint
page: 2705–2718
publication: Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications
Security
publication_identifier:
isbn:
- '9781450394505'
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Bullshark: DAG BFT protocols made practical'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2022'
...
---
_id: '12300'
abstract:
- lang: eng
text: Distributed Key Generation (DKG) is a technique to bootstrap threshold cryptosystems
without a trusted third party and is a building block to decentralized protocols
such as randomness beacons, threshold signatures, and general multiparty computation.
Until recently, DKG protocols have assumed the synchronous model and thus are
vulnerable when their underlying network assumptions do not hold. The recent advancements
in asynchronous DKG protocols are insufficient as they either have poor efficiency
or limited functionality, resulting in a lack of concrete implementations. In
this paper, we present a simple and concretely efficient asynchronous DKG (ADKG)
protocol. In a network of n nodes, our ADKG protocol can tolerate up to t2022 IEEE Symposium on Security and Privacy.
Institute of Electrical and Electronics Engineers; 2022:2518-2534. doi:10.1109/sp46214.2022.9833584'
apa: 'Das, S., Yurek, T., Xiang, Z., Miller, A., Kokoris Kogias, E., & Ren,
L. (2022). Practical asynchronous distributed key generation. In 2022 IEEE
Symposium on Security and Privacy (pp. 2518–2534). San Francisco, CA, United
States: Institute of Electrical and Electronics Engineers. https://doi.org/10.1109/sp46214.2022.9833584'
chicago: Das, Sourav, Thomas Yurek, Zhuolun Xiang, Andrew Miller, Eleftherios Kokoris
Kogias, and Ling Ren. “Practical Asynchronous Distributed Key Generation.” In
2022 IEEE Symposium on Security and Privacy, 2518–34. Institute of Electrical
and Electronics Engineers, 2022. https://doi.org/10.1109/sp46214.2022.9833584.
ieee: S. Das, T. Yurek, Z. Xiang, A. Miller, E. Kokoris Kogias, and L. Ren, “Practical
asynchronous distributed key generation,” in 2022 IEEE Symposium on Security
and Privacy, San Francisco, CA, United States, 2022, pp. 2518–2534.
ista: 'Das S, Yurek T, Xiang Z, Miller A, Kokoris Kogias E, Ren L. 2022. Practical
asynchronous distributed key generation. 2022 IEEE Symposium on Security and Privacy.
SP: Symposium on Security and Privacy, 2518–2534.'
mla: Das, Sourav, et al. “Practical Asynchronous Distributed Key Generation.” 2022
IEEE Symposium on Security and Privacy, Institute of Electrical and Electronics
Engineers, 2022, pp. 2518–34, doi:10.1109/sp46214.2022.9833584.
short: S. Das, T. Yurek, Z. Xiang, A. Miller, E. Kokoris Kogias, L. Ren, in:, 2022
IEEE Symposium on Security and Privacy, Institute of Electrical and Electronics
Engineers, 2022, pp. 2518–2534.
conference:
end_date: 2022-05-26
location: San Francisco, CA, United States
name: 'SP: Symposium on Security and Privacy'
start_date: 2022-05-23
date_created: 2023-01-16T10:06:11Z
date_published: 2022-07-27T00:00:00Z
date_updated: 2023-02-16T07:43:53Z
day: '27'
department:
- _id: ElKo
doi: 10.1109/sp46214.2022.9833584
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2021/1591
month: '07'
oa: 1
oa_version: Preprint
page: 2518-2534
publication: 2022 IEEE Symposium on Security and Privacy
publication_identifier:
eisbn:
- '9781665413169'
eissn:
- 2375-1207
publication_status: published
publisher: Institute of Electrical and Electronics Engineers
quality_controlled: '1'
scopus_import: '1'
status: public
title: Practical asynchronous distributed key generation
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2022'
...
---
_id: '11331'
abstract:
- lang: eng
text: "We propose separating the task of reliable transaction dissemination from
transaction ordering, to enable high-performance Byzantine fault-tolerant quorum-based
consensus. We design and evaluate a mempool protocol, Narwhal, specializing in
high-throughput reliable dissemination and storage of causal histories of transactions.
Narwhal tolerates an asynchronous network and maintains high performance despite
failures. Narwhal is designed to easily scale-out using multiple workers at each
validator, and we demonstrate that there is no foreseeable limit to the throughput
we can achieve.\r\nComposing Narwhal with a partially synchronous consensus protocol
(Narwhal-HotStuff) yields significantly better throughput even in the presence
of faults or intermittent loss of liveness due to asynchrony. However, loss of
liveness can result in higher latency. To achieve overall good performance when
faults occur we design Tusk, a zero-message overhead asynchronous consensus protocol,
to work with Narwhal. We demonstrate its high performance under a variety of configurations
and faults.\r\nAs a summary of results, on a WAN, Narwhal-Hotstuff achieves over
130,000 tx/sec at less than 2-sec latency compared with 1,800 tx/sec at 1-sec
latency for Hotstuff. Additional workers increase throughput linearly to 600,000
tx/sec without any latency increase. Tusk achieves 160,000 tx/sec with about 3
seconds latency. Under faults, both protocols maintain high throughput, but Narwhal-HotStuff
suffers from increased latency."
article_processing_charge: No
author:
- first_name: George
full_name: Danezis, George
last_name: Danezis
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Alberto
full_name: Sonnino, Alberto
last_name: Sonnino
- first_name: Alexander
full_name: Spiegelman, Alexander
last_name: Spiegelman
citation:
ama: 'Danezis G, Kokoris Kogias E, Sonnino A, Spiegelman A. Narwhal and Tusk: A
DAG-based mempool and efficient BFT consensus. In: Proceedings of the 17th
European Conference on Computer Systems. Association for Computing Machinery;
2022:34-50. doi:10.1145/3492321.3519594'
apa: 'Danezis, G., Kokoris Kogias, E., Sonnino, A., & Spiegelman, A. (2022).
Narwhal and Tusk: A DAG-based mempool and efficient BFT consensus. In Proceedings
of the 17th European Conference on Computer Systems (pp. 34–50). Rennes, France:
Association for Computing Machinery. https://doi.org/10.1145/3492321.3519594'
chicago: 'Danezis, George, Eleftherios Kokoris Kogias, Alberto Sonnino, and Alexander
Spiegelman. “Narwhal and Tusk: A DAG-Based Mempool and Efficient BFT Consensus.”
In Proceedings of the 17th European Conference on Computer Systems, 34–50.
Association for Computing Machinery, 2022. https://doi.org/10.1145/3492321.3519594.'
ieee: 'G. Danezis, E. Kokoris Kogias, A. Sonnino, and A. Spiegelman, “Narwhal and
Tusk: A DAG-based mempool and efficient BFT consensus,” in Proceedings of the
17th European Conference on Computer Systems, Rennes, France, 2022, pp. 34–50.'
ista: 'Danezis G, Kokoris Kogias E, Sonnino A, Spiegelman A. 2022. Narwhal and Tusk:
A DAG-based mempool and efficient BFT consensus. Proceedings of the 17th European
Conference on Computer Systems. EuroSys: European Conference on Computer Systems,
34–50.'
mla: 'Danezis, George, et al. “Narwhal and Tusk: A DAG-Based Mempool and Efficient
BFT Consensus.” Proceedings of the 17th European Conference on Computer Systems,
Association for Computing Machinery, 2022, pp. 34–50, doi:10.1145/3492321.3519594.'
short: G. Danezis, E. Kokoris Kogias, A. Sonnino, A. Spiegelman, in:, Proceedings
of the 17th European Conference on Computer Systems, Association for Computing
Machinery, 2022, pp. 34–50.
conference:
end_date: 2022-04-08
location: Rennes, France
name: 'EuroSys: European Conference on Computer Systems'
start_date: 2022-04-05
date_created: 2022-04-24T22:01:43Z
date_published: 2022-03-28T00:00:00Z
date_updated: 2023-08-03T06:38:40Z
day: '28'
department:
- _id: ElKo
doi: 10.1145/3492321.3519594
external_id:
arxiv:
- '2105.11827'
isi:
- '000926506800003'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: ' https://doi.org/10.48550/arXiv.2105.11827'
month: '03'
oa: 1
oa_version: Preprint
page: 34-50
publication: Proceedings of the 17th European Conference on Computer Systems
publication_identifier:
isbn:
- '9781450391627'
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Narwhal and Tusk: A DAG-based mempool and efficient BFT consensus'
type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
year: '2022'
...
---
_id: '12160'
abstract:
- lang: eng
text: We present the Filecoin Hierarchical Consensus framework, which aims to overcome
the throughput challenges of blockchain consensus by horizontally scaling the
network. Unlike traditional sharding designs, based on partitioning the state
of the network, our solution centers on the concept of subnets -which are organized
hierarchically- and can be spawned on-demand to manage new state. Child sub nets
are firewalled from parent subnets, have their own specific policies, and run
a different consensus algorithm, increasing the network capacity and enabling
new applications. Moreover, they benefit from the security of parent subnets by
periodically checkpointing state. In this paper, we introduce the overall system
architecture, our detailed designs for cross-net transaction handling, and the
open questions that we are still exploring.
article_processing_charge: No
author:
- first_name: Alfonso
full_name: De la Rocha, Alfonso
last_name: De la Rocha
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Jorge M.
full_name: Soares, Jorge M.
last_name: Soares
- first_name: Marko
full_name: Vukolic, Marko
last_name: Vukolic
citation:
ama: 'De la Rocha A, Kokoris Kogias E, Soares JM, Vukolic M. Hierarchical consensus:
A horizontal scaling framework for blockchains. In: 42nd International Conference
on Distributed Computing Systems Workshops. Vol 2022. Institute of Electrical
and Electronics Engineers; 2022:45-52. doi:10.1109/icdcsw56584.2022.00018'
apa: 'De la Rocha, A., Kokoris Kogias, E., Soares, J. M., & Vukolic, M. (2022).
Hierarchical consensus: A horizontal scaling framework for blockchains. In 42nd
International Conference on Distributed Computing Systems Workshops (Vol.
2022, pp. 45–52). Bologna, Italy: Institute of Electrical and Electronics Engineers.
https://doi.org/10.1109/icdcsw56584.2022.00018'
chicago: 'De la Rocha, Alfonso, Eleftherios Kokoris Kogias, Jorge M. Soares, and
Marko Vukolic. “Hierarchical Consensus: A Horizontal Scaling Framework for Blockchains.”
In 42nd International Conference on Distributed Computing Systems Workshops,
2022:45–52. Institute of Electrical and Electronics Engineers, 2022. https://doi.org/10.1109/icdcsw56584.2022.00018.'
ieee: 'A. De la Rocha, E. Kokoris Kogias, J. M. Soares, and M. Vukolic, “Hierarchical
consensus: A horizontal scaling framework for blockchains,” in 42nd International
Conference on Distributed Computing Systems Workshops, Bologna, Italy, 2022,
vol. 2022, pp. 45–52.'
ista: 'De la Rocha A, Kokoris Kogias E, Soares JM, Vukolic M. 2022. Hierarchical
consensus: A horizontal scaling framework for blockchains. 42nd International
Conference on Distributed Computing Systems Workshops. ICDCSW: International Conference
on Distributed Computing Systems Workshop vol. 2022, 45–52.'
mla: 'De la Rocha, Alfonso, et al. “Hierarchical Consensus: A Horizontal Scaling
Framework for Blockchains.” 42nd International Conference on Distributed Computing
Systems Workshops, vol. 2022, Institute of Electrical and Electronics Engineers,
2022, pp. 45–52, doi:10.1109/icdcsw56584.2022.00018.'
short: A. De la Rocha, E. Kokoris Kogias, J.M. Soares, M. Vukolic, in:, 42nd International
Conference on Distributed Computing Systems Workshops, Institute of Electrical
and Electronics Engineers, 2022, pp. 45–52.
conference:
end_date: 2022-07-10
location: Bologna, Italy
name: 'ICDCSW: International Conference on Distributed Computing Systems Workshop'
start_date: 2022-07-10
date_created: 2023-01-12T12:09:28Z
date_published: 2022-11-29T00:00:00Z
date_updated: 2023-08-04T09:06:02Z
day: '29'
department:
- _id: ElKo
doi: 10.1109/icdcsw56584.2022.00018
external_id:
isi:
- '000895984800009'
intvolume: ' 2022'
isi: 1
language:
- iso: eng
month: '11'
oa_version: None
page: 45-52
publication: 42nd International Conference on Distributed Computing Systems Workshops
publication_identifier:
eisbn:
- '9781665488792'
eissn:
- 2332-5666
publication_status: published
publisher: Institute of Electrical and Electronics Engineers
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Hierarchical consensus: A horizontal scaling framework for blockchains'
type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 2022
year: '2022'
...
---
_id: '12298'
abstract:
- lang: eng
text: 'Existing committee-based Byzantine state machine replication (SMR) protocols,
typically deployed in production blockchains, face a clear trade-off: (1) they
either achieve linear communication cost in the steady state, but sacrifice liveness
during periods of asynchrony, or (2) they are robust (progress with probability
one) but pay quadratic communication cost. We believe this trade-off is unwarranted
since existing linear protocols still have asymptotic quadratic cost in the worst
case. We design Ditto, a Byzantine SMR protocol that enjoys the best of both worlds:
optimal communication on and off the steady state (linear and quadratic, respectively)
and progress guarantee under asynchrony and DDoS attacks. We achieve this by replacing
the view-synchronization of partially synchronous protocols with an asynchronous
fallback mechanism at no extra asymptotic cost. Specifically, we start from HotStuff,
a state-of-the-art linear protocol, and gradually build Ditto. As a separate contribution
and an intermediate step, we design a 2-chain version of HotStuff, Jolteon, which
leverages a quadratic view-change mechanism to reduce the latency of the standard
3-chain HotStuff. We implement and experimentally evaluate all our systems to
prove that breaking the robustness-efficiency trade-off is in the realm of practicality.'
acknowledgement: We thank our shepherd Aniket Kate and the anonymous reviewers at
FC 2022 for their helpful feedback. This work is supported by the Novi team at Facebook.
We also thank the Novi Research and Engineering teams for valuable feedback, and
in particular Mathieu Baudet, Andrey Chursin, George Danezis, Zekun Li, and Dahlia
Malkhi for discussions that shaped this work.
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Rati
full_name: Gelashvili, Rati
last_name: Gelashvili
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Alberto
full_name: Sonnino, Alberto
last_name: Sonnino
- first_name: Alexander
full_name: Spiegelman, Alexander
last_name: Spiegelman
- first_name: Zhuolun
full_name: Xiang, Zhuolun
last_name: Xiang
citation:
ama: 'Gelashvili R, Kokoris Kogias E, Sonnino A, Spiegelman A, Xiang Z. Jolteon
and ditto: Network-adaptive efficient consensus with asynchronous fallback. In:
Financial Cryptography and Data Security. Vol 13411. Springer Nature; 2022:296-315.
doi:10.1007/978-3-031-18283-9_14'
apa: 'Gelashvili, R., Kokoris Kogias, E., Sonnino, A., Spiegelman, A., & Xiang,
Z. (2022). Jolteon and ditto: Network-adaptive efficient consensus with asynchronous
fallback. In Financial Cryptography and Data Security (Vol. 13411, pp.
296–315). Radisson Grenada Beach Resort, Grenada: Springer Nature. https://doi.org/10.1007/978-3-031-18283-9_14'
chicago: 'Gelashvili, Rati, Eleftherios Kokoris Kogias, Alberto Sonnino, Alexander
Spiegelman, and Zhuolun Xiang. “Jolteon and Ditto: Network-Adaptive Efficient
Consensus with Asynchronous Fallback.” In Financial Cryptography and Data Security,
13411:296–315. Springer Nature, 2022. https://doi.org/10.1007/978-3-031-18283-9_14.'
ieee: 'R. Gelashvili, E. Kokoris Kogias, A. Sonnino, A. Spiegelman, and Z. Xiang,
“Jolteon and ditto: Network-adaptive efficient consensus with asynchronous fallback,”
in Financial Cryptography and Data Security, Radisson Grenada Beach Resort,
Grenada, 2022, vol. 13411, pp. 296–315.'
ista: 'Gelashvili R, Kokoris Kogias E, Sonnino A, Spiegelman A, Xiang Z. 2022. Jolteon
and ditto: Network-adaptive efficient consensus with asynchronous fallback. Financial
Cryptography and Data Security. FC: Financial Cryptography, LNCS, vol. 13411,
296–315.'
mla: 'Gelashvili, Rati, et al. “Jolteon and Ditto: Network-Adaptive Efficient Consensus
with Asynchronous Fallback.” Financial Cryptography and Data Security,
vol. 13411, Springer Nature, 2022, pp. 296–315, doi:10.1007/978-3-031-18283-9_14.'
short: R. Gelashvili, E. Kokoris Kogias, A. Sonnino, A. Spiegelman, Z. Xiang, in:,
Financial Cryptography and Data Security, Springer Nature, 2022, pp. 296–315.
conference:
end_date: 2022-05-06
location: Radisson Grenada Beach Resort, Grenada
name: 'FC: Financial Cryptography'
start_date: 2022-05-02
date_created: 2023-01-16T10:05:51Z
date_published: 2022-10-22T00:00:00Z
date_updated: 2023-09-05T15:13:17Z
day: '22'
department:
- _id: ElKo
doi: 10.1007/978-3-031-18283-9_14
external_id:
arxiv:
- '2106.10362'
intvolume: ' 13411'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: ' https://doi.org/10.48550/arXiv.2106.10362'
month: '10'
oa: 1
oa_version: Preprint
page: 296-315
publication: Financial Cryptography and Data Security
publication_identifier:
eisbn:
- '9783031182839'
eissn:
- 1611-3349
isbn:
- '9783031182822'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Jolteon and ditto: Network-adaptive efficient consensus with asynchronous
fallback'
type: conference
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 13411
year: '2022'
...
---
_id: '12168'
abstract:
- lang: eng
text: "Advances in blockchains have influenced the State-Machine-Replication (SMR)
world and many state-of-the-art blockchain-SMR solutions are based on two pillars:
Chaining and Leader-rotation. A predetermined round-robin mechanism used for Leader-rotation,
however, has an undesirable behavior: crashed parties become designated leaders
infinitely often, slowing down overall system performance. In this paper, we provide
a new Leader-Aware SMR framework that, among other desirable properties, formalizes
a Leader-utilization requirement that bounds the number of rounds whose leaders
are faulty in crash-only executions.\r\nWe introduce Carousel, a novel, reputation-based
Leader-rotation solution to achieve Leader-Aware SMR. The challenge in adaptive
Leader-rotation is that it cannot rely on consensus to determine a leader, since
consensus itself needs a leader. Carousel uses the available on-chain information
to determine a leader locally and achieves Liveness despite this difficulty. A
HotStuff implementation fitted with Carousel demonstrates drastic performance
improvements: it increases throughput over 2x in faultless settings and provided
a 20x throughput increase and 5x latency reduction in the presence of faults."
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Shir
full_name: Cohen, Shir
last_name: Cohen
- first_name: Rati
full_name: Gelashvili, Rati
last_name: Gelashvili
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Zekun
full_name: Li, Zekun
last_name: Li
- first_name: Dahlia
full_name: Malkhi, Dahlia
last_name: Malkhi
- first_name: Alberto
full_name: Sonnino, Alberto
last_name: Sonnino
- first_name: Alexander
full_name: Spiegelman, Alexander
last_name: Spiegelman
citation:
ama: 'Cohen S, Gelashvili R, Kokoris Kogias E, et al. Be aware of your leaders.
In: International Conference on Financial Cryptography and Data Security.
Vol 13411. Springer Nature; 2022:279-295. doi:10.1007/978-3-031-18283-9_13'
apa: 'Cohen, S., Gelashvili, R., Kokoris Kogias, E., Li, Z., Malkhi, D., Sonnino,
A., & Spiegelman, A. (2022). Be aware of your leaders. In International
Conference on Financial Cryptography and Data Security (Vol. 13411, pp. 279–295).
Grenada: Springer Nature. https://doi.org/10.1007/978-3-031-18283-9_13'
chicago: Cohen, Shir, Rati Gelashvili, Eleftherios Kokoris Kogias, Zekun Li, Dahlia
Malkhi, Alberto Sonnino, and Alexander Spiegelman. “Be Aware of Your Leaders.”
In International Conference on Financial Cryptography and Data Security,
13411:279–95. Springer Nature, 2022. https://doi.org/10.1007/978-3-031-18283-9_13.
ieee: S. Cohen et al., “Be aware of your leaders,” in International Conference
on Financial Cryptography and Data Security, Grenada, 2022, vol. 13411, pp.
279–295.
ista: 'Cohen S, Gelashvili R, Kokoris Kogias E, Li Z, Malkhi D, Sonnino A, Spiegelman
A. 2022. Be aware of your leaders. International Conference on Financial Cryptography
and Data Security. FC: Financial Cryptography and Data Security, LNCS, vol. 13411,
279–295.'
mla: Cohen, Shir, et al. “Be Aware of Your Leaders.” International Conference
on Financial Cryptography and Data Security, vol. 13411, Springer Nature,
2022, pp. 279–95, doi:10.1007/978-3-031-18283-9_13.
short: S. Cohen, R. Gelashvili, E. Kokoris Kogias, Z. Li, D. Malkhi, A. Sonnino,
A. Spiegelman, in:, International Conference on Financial Cryptography and Data
Security, Springer Nature, 2022, pp. 279–295.
conference:
end_date: 2022-05-06
location: Grenada
name: 'FC: Financial Cryptography and Data Security'
start_date: 2022-05-02
date_created: 2023-01-12T12:10:49Z
date_published: 2022-10-22T00:00:00Z
date_updated: 2023-09-05T15:11:35Z
day: '22'
department:
- _id: ElKo
doi: 10.1007/978-3-031-18283-9_13
external_id:
arxiv:
- '2110.00960'
intvolume: ' 13411'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.48550/arXiv.2110.00960
month: '10'
oa: 1
oa_version: Preprint
page: 279-295
publication: International Conference on Financial Cryptography and Data Security
publication_identifier:
eisbn:
- '9783031182839'
eissn:
- 1611-3349
isbn:
- '9783031182822'
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Be aware of your leaders
type: conference
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 13411
year: '2022'
...
---
_id: '10076'
abstract:
- lang: eng
text: We present a novel approach for blockchain asset owners to reclaim their funds
in case of accidental private-key loss or transfer to a mistyped address. Our
solution can be deployed upon failure or absence of proactively implemented backup
mechanisms, such as secret sharing and cold storage. The main advantages against
previous proposals is it does not require any prior action from users and works
with both single-key and multi-sig accounts. We achieve this by a 3-phase Commit()→Reveal()→Claim()−or−Challenge() smart
contract that enables accessing funds of addresses for which the spending key
is not available. We provide an analysis of the threat and incentive models and
formalize the concept of reactive KEy-Loss Protection (KELP).
acknowledgement: The authors would like to thank all anonymous reviewers of FC21 WTSC
workshop for comments and suggestions that greatly improved the quality of this
paper.
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Sam
full_name: Blackshear, Sam
last_name: Blackshear
- first_name: Konstantinos
full_name: Chalkias, Konstantinos
last_name: Chalkias
- first_name: Panagiotis
full_name: Chatzigiannis, Panagiotis
last_name: Chatzigiannis
- first_name: Riyaz
full_name: Faizullabhoy, Riyaz
last_name: Faizullabhoy
- first_name: Irakliy
full_name: Khaburzaniya, Irakliy
last_name: Khaburzaniya
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Joshua
full_name: Lind, Joshua
last_name: Lind
- first_name: David
full_name: Wong, David
last_name: Wong
- first_name: Tim
full_name: Zakian, Tim
last_name: Zakian
citation:
ama: 'Blackshear S, Chalkias K, Chatzigiannis P, et al. Reactive key-loss protection
in blockchains. In: FC 2021 Workshops. Vol 12676. Springer Nature; 2021:431-450.
doi:10.1007/978-3-662-63958-0_34'
apa: 'Blackshear, S., Chalkias, K., Chatzigiannis, P., Faizullabhoy, R., Khaburzaniya,
I., Kokoris Kogias, E., … Zakian, T. (2021). Reactive key-loss protection in blockchains.
In FC 2021 Workshops (Vol. 12676, pp. 431–450). Virtual: Springer Nature.
https://doi.org/10.1007/978-3-662-63958-0_34'
chicago: Blackshear, Sam, Konstantinos Chalkias, Panagiotis Chatzigiannis, Riyaz
Faizullabhoy, Irakliy Khaburzaniya, Eleftherios Kokoris Kogias, Joshua Lind, David
Wong, and Tim Zakian. “Reactive Key-Loss Protection in Blockchains.” In FC
2021 Workshops, 12676:431–50. Springer Nature, 2021. https://doi.org/10.1007/978-3-662-63958-0_34.
ieee: S. Blackshear et al., “Reactive key-loss protection in blockchains,”
in FC 2021 Workshops, Virtual, 2021, vol. 12676, pp. 431–450.
ista: 'Blackshear S, Chalkias K, Chatzigiannis P, Faizullabhoy R, Khaburzaniya I,
Kokoris Kogias E, Lind J, Wong D, Zakian T. 2021. Reactive key-loss protection
in blockchains. FC 2021 Workshops. FC: International Conference on Financial Cryptography
and Data Security, LNCS, vol. 12676, 431–450.'
mla: Blackshear, Sam, et al. “Reactive Key-Loss Protection in Blockchains.” FC
2021 Workshops, vol. 12676, Springer Nature, 2021, pp. 431–50, doi:10.1007/978-3-662-63958-0_34.
short: S. Blackshear, K. Chalkias, P. Chatzigiannis, R. Faizullabhoy, I. Khaburzaniya,
E. Kokoris Kogias, J. Lind, D. Wong, T. Zakian, in:, FC 2021 Workshops, Springer
Nature, 2021, pp. 431–450.
conference:
end_date: 2021-03-05
location: Virtual
name: 'FC: International Conference on Financial Cryptography and Data Security'
start_date: 2021-03-01
date_created: 2021-10-03T22:01:24Z
date_published: 2021-09-17T00:00:00Z
date_updated: 2023-08-14T07:06:16Z
day: '17'
department:
- _id: ElKo
doi: 10.1007/978-3-662-63958-0_34
external_id:
isi:
- '000713005000034'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://research.fb.com/publications/reactive-key-loss-protection-in-blockchains/
month: '09'
oa: 1
oa_version: Preprint
page: 431-450
publication: FC 2021 Workshops
publication_identifier:
eisbn:
- 978-3-662-63958-0
eissn:
- 1611-3349
isbn:
- 978-3-6626-3957-3
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Reactive key-loss protection in blockchains
type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: '12676 '
year: '2021'
...
---
_id: '10325'
abstract:
- lang: eng
text: Since the inception of Bitcoin, a plethora of distributed ledgers differing
in design and purpose has been created. While by design, blockchains provide no
means to securely communicate with external systems, numerous attempts towards
trustless cross-chain communication have been proposed over the years. Today,
cross-chain communication (CCC) plays a fundamental role in cryptocurrency exchanges,
scalability efforts via sharding, extension of existing systems through sidechains,
and bootstrapping of new blockchains. Unfortunately, existing proposals are designed
ad-hoc for specific use-cases, making it hard to gain confidence in their correctness
and composability. We provide the first systematic exposition of cross-chain communication
protocols. We formalize the underlying research problem and show that CCC is impossible
without a trusted third party, contrary to common beliefs in the blockchain community.
With this result in mind, we develop a framework to design new and evaluate existing
CCC protocols, focusing on the inherent trust assumptions thereof, and derive
a classification covering the field of cross-chain communication to date. We conclude
by discussing open challenges for CCC research and the implications of interoperability
on the security and privacy of blockchains.
acknowledgement: 'We would like express our gratitude to Georgia Avarikioti, Daniel
Perez and Dominik Harz for helpful comments and feedback on earlier versions of
this manuscript. We also thank Nicholas Stifter, Aljosha Judmayer, Philipp Schindler,
Edgar Weippl, and Alistair Stewart for insightful discussions during the early stages
of this research. We also wish to thank the anonymous reviewers for their valuable
comments that helped improve the presentation of our results. This research was
funded by Bridge 1 858561 SESC; Bridge 1 864738 PR4DLT (all FFG); the Christian
Doppler Laboratory for Security and Quality Improvement in the Production System
Lifecycle (CDL-SQI); the competence center SBA-K1 funded by COMET; Chaincode Labs
through the project SLN: Scalability for the Lightning Network; and by the Austrian
Science Fund (FWF) through the Meitner program (project M-2608). Mustafa Al-Bassam
is funded by a scholarship from the Alan Turing Institute. Alexei Zamyatin conducted
the early stages of this work during his time at SBA Research, and was supported
by a Binance Research Fellowship.'
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Alexei
full_name: Zamyatin, Alexei
last_name: Zamyatin
- first_name: Mustafa
full_name: Al-Bassam, Mustafa
last_name: Al-Bassam
- first_name: Dionysis
full_name: Zindros, Dionysis
last_name: Zindros
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Pedro
full_name: Moreno-Sanchez, Pedro
last_name: Moreno-Sanchez
- first_name: Aggelos
full_name: Kiayias, Aggelos
last_name: Kiayias
- first_name: William J.
full_name: Knottenbelt, William J.
last_name: Knottenbelt
citation:
ama: 'Zamyatin A, Al-Bassam M, Zindros D, et al. SoK: Communication across distributed
ledgers. In: 25th International Conference on Financial Cryptography and Data
Security. Vol 12675. Springer Nature; 2021:3-36. doi:10.1007/978-3-662-64331-0_1'
apa: 'Zamyatin, A., Al-Bassam, M., Zindros, D., Kokoris Kogias, E., Moreno-Sanchez,
P., Kiayias, A., & Knottenbelt, W. J. (2021). SoK: Communication across distributed
ledgers. In 25th International Conference on Financial Cryptography and Data
Security (Vol. 12675, pp. 3–36). Virtual: Springer Nature. https://doi.org/10.1007/978-3-662-64331-0_1'
chicago: 'Zamyatin, Alexei, Mustafa Al-Bassam, Dionysis Zindros, Eleftherios Kokoris
Kogias, Pedro Moreno-Sanchez, Aggelos Kiayias, and William J. Knottenbelt. “SoK:
Communication across Distributed Ledgers.” In 25th International Conference
on Financial Cryptography and Data Security, 12675:3–36. Springer Nature,
2021. https://doi.org/10.1007/978-3-662-64331-0_1.'
ieee: 'A. Zamyatin et al., “SoK: Communication across distributed ledgers,”
in 25th International Conference on Financial Cryptography and Data Security,
Virtual, 2021, vol. 12675, pp. 3–36.'
ista: 'Zamyatin A, Al-Bassam M, Zindros D, Kokoris Kogias E, Moreno-Sanchez P, Kiayias
A, Knottenbelt WJ. 2021. SoK: Communication across distributed ledgers. 25th International
Conference on Financial Cryptography and Data Security. FC: Financial Cryptography,
LNCS, vol. 12675, 3–36.'
mla: 'Zamyatin, Alexei, et al. “SoK: Communication across Distributed Ledgers.”
25th International Conference on Financial Cryptography and Data Security,
vol. 12675, Springer Nature, 2021, pp. 3–36, doi:10.1007/978-3-662-64331-0_1.'
short: A. Zamyatin, M. Al-Bassam, D. Zindros, E. Kokoris Kogias, P. Moreno-Sanchez,
A. Kiayias, W.J. Knottenbelt, in:, 25th International Conference on Financial
Cryptography and Data Security, Springer Nature, 2021, pp. 3–36.
conference:
end_date: 2021-03-05
location: Virtual
name: 'FC: Financial Cryptography'
start_date: 2021-03-01
date_created: 2021-11-21T23:01:29Z
date_published: 2021-10-23T00:00:00Z
date_updated: 2023-08-14T12:59:26Z
day: '23'
department:
- _id: ElKo
doi: 10.1007/978-3-662-64331-0_1
external_id:
isi:
- '000712016200001'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2019/1128
month: '10'
oa: 1
oa_version: Preprint
page: 3-36
publication: 25th International Conference on Financial Cryptography and Data Security
publication_identifier:
eisbn:
- 978-3-662-64331-0
eissn:
- 1611-3349
isbn:
- 9-783-6626-4330-3
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'SoK: Communication across distributed ledgers'
type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: '12675 '
year: '2021'
...
---
_id: '10324'
abstract:
- lang: eng
text: Off-chain protocols (channels) are a promising solution to the scalability
and privacy challenges of blockchain payments. Current proposals, however, require
synchrony assumptions to preserve the safety of a channel, leaking to an adversary
the exact amount of time needed to control the network for a successful attack.
In this paper, we introduce Brick, the first payment channel that remains secure
under network asynchrony and concurrently provides correct incentives. The core
idea is to incorporate the conflict resolution process within the channel by introducing
a rational committee of external parties, called wardens. Hence, if a party wants
to close a channel unilaterally, it can only get the committee’s approval for
the last valid state. Additionally, Brick provides sub-second latency because
it does not employ heavy-weight consensus. Instead, Brick uses consistent broadcast
to announce updates and close the channel, a light-weight abstraction that is
powerful enough to preserve safety and liveness to any rational parties. We formally
define and prove for Brick the properties a payment channel construction should
fulfill. We also design incentives for Brick such that honest and rational behavior
aligns. Finally, we provide a reference implementation of the smart contracts
in Solidity.
acknowledgement: We would like to thank Kaoutar Elkhiyaoui for her valuable feedback
as well as Jakub Sliwinski for his impactful contribution to this work.
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Zeta
full_name: Avarikioti, Zeta
last_name: Avarikioti
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Roger
full_name: Wattenhofer, Roger
last_name: Wattenhofer
- first_name: Dionysis
full_name: Zindros, Dionysis
last_name: Zindros
citation:
ama: 'Avarikioti Z, Kokoris Kogias E, Wattenhofer R, Zindros D. Brick: Asynchronous
incentive-compatible payment channels. In: 25th International Conference on
Financial Cryptography and Data Security. Vol 12675. Springer Nature; 2021:209-230.
doi:10.1007/978-3-662-64331-0_11'
apa: 'Avarikioti, Z., Kokoris Kogias, E., Wattenhofer, R., & Zindros, D. (2021).
Brick: Asynchronous incentive-compatible payment channels. In 25th International
Conference on Financial Cryptography and Data Security (Vol. 12675, pp. 209–230).
Virtual: Springer Nature. https://doi.org/10.1007/978-3-662-64331-0_11'
chicago: 'Avarikioti, Zeta, Eleftherios Kokoris Kogias, Roger Wattenhofer, and Dionysis
Zindros. “Brick: Asynchronous Incentive-Compatible Payment Channels.” In 25th
International Conference on Financial Cryptography and Data Security, 12675:209–30.
Springer Nature, 2021. https://doi.org/10.1007/978-3-662-64331-0_11.'
ieee: 'Z. Avarikioti, E. Kokoris Kogias, R. Wattenhofer, and D. Zindros, “Brick:
Asynchronous incentive-compatible payment channels,” in 25th International
Conference on Financial Cryptography and Data Security, Virtual, 2021, vol.
12675, pp. 209–230.'
ista: 'Avarikioti Z, Kokoris Kogias E, Wattenhofer R, Zindros D. 2021. Brick: Asynchronous
incentive-compatible payment channels. 25th International Conference on Financial
Cryptography and Data Security. FC: Financial Cryptography, LNCS, vol. 12675,
209–230.'
mla: 'Avarikioti, Zeta, et al. “Brick: Asynchronous Incentive-Compatible Payment
Channels.” 25th International Conference on Financial Cryptography and Data
Security, vol. 12675, Springer Nature, 2021, pp. 209–30, doi:10.1007/978-3-662-64331-0_11.'
short: Z. Avarikioti, E. Kokoris Kogias, R. Wattenhofer, D. Zindros, in:, 25th International
Conference on Financial Cryptography and Data Security, Springer Nature, 2021,
pp. 209–230.
conference:
end_date: 2021-03-05
location: Virtual
name: 'FC: Financial Cryptography'
start_date: 2021-03-01
date_created: 2021-11-21T23:01:29Z
date_published: 2021-10-23T00:00:00Z
date_updated: 2023-08-14T12:59:58Z
day: '23'
department:
- _id: ElKo
doi: 10.1007/978-3-662-64331-0_11
external_id:
arxiv:
- '1905.11360'
isi:
- '000712016200011'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1905.11360
month: '10'
oa: 1
oa_version: Preprint
page: 209-230
publication: 25th International Conference on Financial Cryptography and Data Security
publication_identifier:
eisbn:
- 978-3-662-64331-0
eissn:
- 1611-3349
isbn:
- 9-783-6626-4330-3
issn:
- 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Brick: Asynchronous incentive-compatible payment channels'
type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: '12675 '
year: '2021'
...
---
_id: '10554'
abstract:
- lang: eng
text: 'We present DAG-Rider, the first asynchronous Byzantine Atomic Broadcast protocol
that achieves optimal resilience, optimal amortized communication complexity,
and optimal time complexity. DAG-Rider is post-quantum safe and ensures that all
values proposed by correct processes eventually get delivered. We construct DAG-Rider
in two layers: In the first layer, processes reliably broadcast their proposals
and build a structured Directed Acyclic Graph (DAG) of the communication among
them. In the second layer, processes locally observe their DAGs and totally order
all proposals with no extra communication.'
acknowledgement: "Oded Naor is grateful to the Technion Hiroshi Fujiwara Cyber-Security
Research Center for providing a research grant. Part of Oded’s work was done while
at Novi Research. This work was funded by the Novi team at Facebook. We also wish
to thank the Novi Research team for valuable feedback, and in particular George
Danezis, Alberto Sonnino, and Dahlia Malkhi.\r\n"
article_processing_charge: No
author:
- first_name: Idit
full_name: Keidar, Idit
last_name: Keidar
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Oded
full_name: Naor, Oded
last_name: Naor
- first_name: Alexander
full_name: Spiegelman, Alexander
last_name: Spiegelman
citation:
ama: 'Keidar I, Kokoris Kogias E, Naor O, Spiegelman A. All You Need is DAG. In:
Proceedings of the 2021 ACM Symposium on Principles of Distributed Computing.
Association for Computing Machinery; 2021:165-175. doi:10.1145/3465084.3467905'
apa: 'Keidar, I., Kokoris Kogias, E., Naor, O., & Spiegelman, A. (2021). All
You Need is DAG. In Proceedings of the 2021 ACM Symposium on Principles of
Distributed Computing (pp. 165–175). Virtual, Italy: Association for Computing
Machinery. https://doi.org/10.1145/3465084.3467905'
chicago: Keidar, Idit, Eleftherios Kokoris Kogias, Oded Naor, and Alexander Spiegelman.
“All You Need Is DAG.” In Proceedings of the 2021 ACM Symposium on Principles
of Distributed Computing, 165–75. Association for Computing Machinery, 2021.
https://doi.org/10.1145/3465084.3467905.
ieee: I. Keidar, E. Kokoris Kogias, O. Naor, and A. Spiegelman, “All You Need is
DAG,” in Proceedings of the 2021 ACM Symposium on Principles of Distributed
Computing, Virtual, Italy, 2021, pp. 165–175.
ista: 'Keidar I, Kokoris Kogias E, Naor O, Spiegelman A. 2021. All You Need is DAG.
Proceedings of the 2021 ACM Symposium on Principles of Distributed Computing.
PODC: Principles of Distributed Computing, 165–175.'
mla: Keidar, Idit, et al. “All You Need Is DAG.” Proceedings of the 2021 ACM
Symposium on Principles of Distributed Computing, Association for Computing
Machinery, 2021, pp. 165–75, doi:10.1145/3465084.3467905.
short: I. Keidar, E. Kokoris Kogias, O. Naor, A. Spiegelman, in:, Proceedings of
the 2021 ACM Symposium on Principles of Distributed Computing, Association for
Computing Machinery, 2021, pp. 165–175.
conference:
end_date: 2021-07-30
location: Virtual, Italy
name: 'PODC: Principles of Distributed Computing'
start_date: 2021-07-26
date_created: 2021-12-16T13:21:13Z
date_published: 2021-07-21T00:00:00Z
date_updated: 2023-08-17T06:24:44Z
day: '21'
department:
- _id: ElKo
doi: 10.1145/3465084.3467905
external_id:
arxiv:
- '2102.08325'
isi:
- '000744439800016'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2102.08325
month: '07'
oa: 1
oa_version: Preprint
page: 165-175
publication: Proceedings of the 2021 ACM Symposium on Principles of Distributed Computing
publication_identifier:
isbn:
- 978-1-4503-8548-0
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: All You Need is DAG
type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
year: '2021'
...
---
_id: '10553'
abstract:
- lang: eng
text: The popularity of permissioned blockchain systems demands BFT SMR protocols
that are efficient under good network conditions (synchrony) and robust under
bad network conditions (asynchrony). The state-of-the-art partially synchronous
BFT SMR protocols provide optimal linear communication cost per decision under
synchrony and good leaders, but lose liveness under asynchrony. On the other hand,
the state-of-the-art asynchronous BFT SMR protocols are live even under asynchrony,
but always pay quadratic cost even under synchrony. In this paper, we propose
a BFT SMR protocol that achieves the best of both worlds -- optimal linear cost
per decision under good networks and leaders, optimal quadratic cost per decision
under bad networks, and remains always live.
article_processing_charge: No
author:
- first_name: Rati
full_name: Gelashvili, Rati
last_name: Gelashvili
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Alexander
full_name: Spiegelman, Alexander
last_name: Spiegelman
- first_name: Zhuolun
full_name: Xiang, Zhuolun
last_name: Xiang
citation:
ama: 'Gelashvili R, Kokoris Kogias E, Spiegelman A, Xiang Z. Brief announcement:
Be prepared when network goes bad: An asynchronous view-change protocol. In: Proceedings
of the 2021 ACM Symposium on Principles of Distributed Computing. Association
for Computing Machinery; 2021:187-190. doi:10.1145/3465084.3467941'
apa: 'Gelashvili, R., Kokoris Kogias, E., Spiegelman, A., & Xiang, Z. (2021).
Brief announcement: Be prepared when network goes bad: An asynchronous view-change
protocol. In Proceedings of the 2021 ACM Symposium on Principles of Distributed
Computing (pp. 187–190). Virtual, Italy: Association for Computing Machinery.
https://doi.org/10.1145/3465084.3467941'
chicago: 'Gelashvili, Rati, Eleftherios Kokoris Kogias, Alexander Spiegelman, and
Zhuolun Xiang. “Brief Announcement: Be Prepared When Network Goes Bad: An Asynchronous
View-Change Protocol.” In Proceedings of the 2021 ACM Symposium on Principles
of Distributed Computing, 187–90. Association for Computing Machinery, 2021.
https://doi.org/10.1145/3465084.3467941.'
ieee: 'R. Gelashvili, E. Kokoris Kogias, A. Spiegelman, and Z. Xiang, “Brief announcement:
Be prepared when network goes bad: An asynchronous view-change protocol,” in Proceedings
of the 2021 ACM Symposium on Principles of Distributed Computing, Virtual,
Italy, 2021, pp. 187–190.'
ista: 'Gelashvili R, Kokoris Kogias E, Spiegelman A, Xiang Z. 2021. Brief announcement:
Be prepared when network goes bad: An asynchronous view-change protocol. Proceedings
of the 2021 ACM Symposium on Principles of Distributed Computing. PODC: Principles
of Distributed Computing, 187–190.'
mla: 'Gelashvili, Rati, et al. “Brief Announcement: Be Prepared When Network Goes
Bad: An Asynchronous View-Change Protocol.” Proceedings of the 2021 ACM Symposium
on Principles of Distributed Computing, Association for Computing Machinery,
2021, pp. 187–90, doi:10.1145/3465084.3467941.'
short: R. Gelashvili, E. Kokoris Kogias, A. Spiegelman, Z. Xiang, in:, Proceedings
of the 2021 ACM Symposium on Principles of Distributed Computing, Association
for Computing Machinery, 2021, pp. 187–190.
conference:
end_date: 2021-07-30
location: Virtual, Italy
name: 'PODC: Principles of Distributed Computing'
start_date: 2021-07-26
date_created: 2021-12-16T13:20:19Z
date_published: 2021-07-21T00:00:00Z
date_updated: 2023-09-04T11:42:10Z
day: '21'
department:
- _id: ElKo
doi: 10.1145/3465084.3467941
external_id:
arxiv:
- '2103.03181'
isi:
- '000744439800018'
isi: 1
keyword:
- optimal
- state machine replication
- fallback
- asynchrony
- byzantine faults
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2103.03181
month: '07'
oa: 1
oa_version: Preprint
page: 187-190
publication: Proceedings of the 2021 ACM Symposium on Principles of Distributed Computing
publication_identifier:
isbn:
- 9-781-4503-8548-0
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Brief announcement: Be prepared when network goes bad: An asynchronous view-change
protocol'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2021'
...
---
_id: '10557'
abstract:
- lang: eng
text: Data storage and retrieval systems, methods, and computer-readable media utilize
a cryptographically verifiable data structure that facilitates verification of
a transaction in a decentralized peer-to-peer environment using multi-hop backwards
and forwards links. Backward links are cryptographic hashes of past records. Forward
links are cryptographic signatures of future records that are added retroactively
to records once the target block has been appended to the data structure.
applicant:
- Ecole Polytechnique Federale de Lausanne
application_date: 2017-06-09
article_processing_charge: No
author:
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
- first_name: Linus
full_name: Gasse, Linus
last_name: Gasse
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Philipp
full_name: Jovanovic, Philipp
last_name: Jovanovic
citation:
ama: Ford B, Gasse L, Kokoris Kogias E, Jovanovic P. Cryptographically verifiable
data structure having multi-hop forward and backwards links and associated systems
and methods. 2020.
apa: Ford, B., Gasse, L., Kokoris Kogias, E., & Jovanovic, P. (2020). Cryptographically
verifiable data structure having multi-hop forward and backwards links and associated
systems and methods.
chicago: Ford, Bryan, Linus Gasse, Eleftherios Kokoris Kogias, and Philipp Jovanovic.
“Cryptographically Verifiable Data Structure Having Multi-Hop Forward and Backwards
Links and Associated Systems and Methods,” 2020.
ieee: B. Ford, L. Gasse, E. Kokoris Kogias, and P. Jovanovic, “Cryptographically
verifiable data structure having multi-hop forward and backwards links and associated
systems and methods.” 2020.
ista: Ford B, Gasse L, Kokoris Kogias E, Jovanovic P. 2020. Cryptographically verifiable
data structure having multi-hop forward and backwards links and associated systems
and methods.
mla: Ford, Bryan, et al. Cryptographically Verifiable Data Structure Having Multi-Hop
Forward and Backwards Links and Associated Systems and Methods. 2020.
short: B. Ford, L. Gasse, E. Kokoris Kogias, P. Jovanovic, (2020).
date_created: 2021-12-16T13:28:59Z
date_published: 2020-03-03T00:00:00Z
date_updated: 2021-12-21T10:04:50Z
day: '03'
department:
- _id: ElKo
extern: '1'
ipc: ' H04L9/3247 ; G06Q20/29 ; G06Q20/382 ; H04L9/3236'
ipn: '10581613'
main_file_link:
- open_access: '1'
url: https://patents.google.com/patent/US10581613B2/en
month: '03'
oa: 1
oa_version: Published Version
publication_date: 2020-03-03
related_material:
link:
- relation: earlier_version
url: https://patents.google.com/patent/US20180359096A1/en
status: public
title: Cryptographically verifiable data structure having multi-hop forward and backwards
links and associated systems and methods
type: patent
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2020'
...
---
_id: '8307'
abstract:
- lang: eng
text: "Classic Byzantine fault-tolerant consensus protocols forfeit liveness in
the face of asynchrony in order to preserve safety, whereas most deployed blockchain
protocols forfeit safety in order to remain live. In this work, we achieve the
best of both worlds by proposing a novel abstractions called the finality gadget.
A finality gadget allows for transactions to always optimistically commit but
informs the clients that these transactions might be unsafe. As a result, a blockchain
can execute transactions optimistically and only commit them after they have been
sufficiently and provably audited. In\r\nthis work, we formally model the finality
gadget abstraction, prove that it is impossible to solve it deterministically
in full asynchrony (even though it is stronger than consensus) and provide a partially
synchronous protocol which is currently securing a major blockchain. This way
we show that the protocol designer can decouple safety and liveness in order to
speed up recovery from failures. We believe that there can be other types of finality
gadgets that provide weaker safety (e.g., probabilistic) in order to gain more
efficiency and this can depend on the probability that the network is not in synchrony."
article_number: '2007.01560'
article_processing_charge: No
author:
- first_name: Alistair
full_name: Stewart, Alistair
last_name: Stewart
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
citation:
ama: 'Stewart A, Kokoris Kogias E. GRANDPA: A Byzantine finality gadget. arXiv.'
apa: 'Stewart, A., & Kokoris Kogias, E. (n.d.). GRANDPA: A Byzantine finality
gadget. arXiv.'
chicago: 'Stewart, Alistair, and Eleftherios Kokoris Kogias. “GRANDPA: A Byzantine
Finality Gadget.” ArXiv, n.d.'
ieee: 'A. Stewart and E. Kokoris Kogias, “GRANDPA: A Byzantine finality gadget,”
arXiv. .'
ista: 'Stewart A, Kokoris Kogias E. GRANDPA: A Byzantine finality gadget. arXiv,
2007.01560.'
mla: 'Stewart, Alistair, and Eleftherios Kokoris Kogias. “GRANDPA: A Byzantine Finality
Gadget.” ArXiv, 2007.01560.'
short: A. Stewart, E. Kokoris Kogias, ArXiv (n.d.).
date_created: 2020-08-26T12:32:10Z
date_published: 2020-07-03T00:00:00Z
date_updated: 2021-01-12T08:18:02Z
day: '03'
extern: '1'
external_id:
arxiv:
- '2007.01560'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2007.01560
month: '07'
oa: 1
oa_version: Preprint
publication: arXiv
publication_status: submitted
status: public
title: 'GRANDPA: A Byzantine finality gadget'
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2020'
...
---
_id: '9011'
abstract:
- lang: eng
text: "Distributed ledgers provide high availability and integrity, making them
a key enabler for practical and secure computation of distributed workloads among
mutually distrustful parties. Many practical applications also require strong
confidentiality, however. This work enhances permissioned and permissionless blockchains
with the ability to manage confidential data without forfeiting availability or
decentralization. The proposed Calypso architecture addresses two orthogonal challenges
confronting modern distributed ledgers: (a) enabling the auditable management
of secrets and (b) protecting distributed computations against arbitrage attacks
when their results depend on the ordering and secrecy of inputs.\r\n\r\nCalypso
introduces on-chain secrets, a novel abstraction that enforces atomic deposition
of an auditable trace whenever users access confidential data. Calypso provides
user-controlled consent management that ensures revocation atomicity and accountable
anonymity. To enable permissionless deployment, we introduce an incentive scheme
and provide users with the option to select their preferred trustees. We evaluated
our Calypso prototype with a confidential document-sharing application and a decentralized
lottery. Our benchmarks show that transaction-processing latency increases linearly
in terms of security (number of trustees) and is in the range of 0.2 to 8 seconds
for 16 to 128 trustees."
acknowledgement: 'We thank Nicolas Gailly, Vincent Graf, Jean-Pierre Hubaux, Wouter
Lueks, Massimo Marelli, Carmela Troncoso, Juan-Ramón Troncoso Pastoriza, Frédéric
Pont, and Sandra Siby for their valuable feedback. This project was supported in
part by the ETH domain under PHRT grant #2017−201, and by the AXA Research Fund,
Byzgen, DFINITY, and the Swiss Data Science Center (SDSC).'
article_processing_charge: No
article_type: original
author:
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Enis Ceyhun
full_name: Alp, Enis Ceyhun
last_name: Alp
- first_name: Linus
full_name: Gasser, Linus
last_name: Gasser
- first_name: Philipp
full_name: Jovanovic, Philipp
last_name: Jovanovic
- first_name: Ewa
full_name: Syta, Ewa
last_name: Syta
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
citation:
ama: 'Kokoris Kogias E, Alp EC, Gasser L, Jovanovic P, Syta E, Ford B. CALYPSO:
Private data management for decentralized ledgers. Proceedings of the VLDB
Endowment. 2020;14(4):586-599. doi:10.14778/3436905.3436917'
apa: 'Kokoris Kogias, E., Alp, E. C., Gasser, L., Jovanovic, P., Syta, E., &
Ford, B. (2020). CALYPSO: Private data management for decentralized ledgers. Proceedings
of the VLDB Endowment. Association for Computing Machinery. https://doi.org/10.14778/3436905.3436917'
chicago: 'Kokoris Kogias, Eleftherios, Enis Ceyhun Alp, Linus Gasser, Philipp Jovanovic,
Ewa Syta, and Bryan Ford. “CALYPSO: Private Data Management for Decentralized
Ledgers.” Proceedings of the VLDB Endowment. Association for Computing
Machinery, 2020. https://doi.org/10.14778/3436905.3436917.'
ieee: 'E. Kokoris Kogias, E. C. Alp, L. Gasser, P. Jovanovic, E. Syta, and B. Ford,
“CALYPSO: Private data management for decentralized ledgers,” Proceedings of
the VLDB Endowment, vol. 14, no. 4. Association for Computing Machinery, pp.
586–599, 2020.'
ista: 'Kokoris Kogias E, Alp EC, Gasser L, Jovanovic P, Syta E, Ford B. 2020. CALYPSO:
Private data management for decentralized ledgers. Proceedings of the VLDB Endowment.
14(4), 586–599.'
mla: 'Kokoris Kogias, Eleftherios, et al. “CALYPSO: Private Data Management for
Decentralized Ledgers.” Proceedings of the VLDB Endowment, vol. 14, no.
4, Association for Computing Machinery, 2020, pp. 586–99, doi:10.14778/3436905.3436917.'
short: E. Kokoris Kogias, E.C. Alp, L. Gasser, P. Jovanovic, E. Syta, B. Ford, Proceedings
of the VLDB Endowment 14 (2020) 586–599.
date_created: 2021-01-17T23:01:13Z
date_published: 2020-12-01T00:00:00Z
date_updated: 2023-08-24T13:57:13Z
day: '01'
department:
- _id: ElKo
doi: 10.14778/3436905.3436917
external_id:
isi:
- '000658495400012'
intvolume: ' 14'
isi: 1
issue: '4'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://dl.acm.org/doi/10.14778/3436905.3436917
month: '12'
oa: 1
oa_version: Published Version
page: 586-599
publication: Proceedings of the VLDB Endowment
publication_identifier:
eissn:
- 2150-8097
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'CALYPSO: Private data management for decentralized ledgers'
tmp:
image: /images/cc_by_nc_nd.png
legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode
name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
(CC BY-NC-ND 4.0)
short: CC BY-NC-ND (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 14
year: '2020'
...
---
_id: '10556'
abstract:
- lang: eng
text: In this paper, we present the first Asynchronous Distributed Key Generation
(ADKG) algorithm which is also the first distributed key generation algorithm
that can generate cryptographic keys with a dual (f,2f+1)-threshold (where f is
the number of faulty parties). As a result, using our ADKG we remove the trusted
setup assumption that the most scalable consensus algorithms make. In order to
create a DKG with a dual (f,2f+1)- threshold we first answer in the affirmative
the open question posed by Cachin et al. [7] on how to create an Asynchronous
Verifiable Secret Sharing (AVSS) protocol with a reconstruction threshold of f+1Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications
Security. Association for Computing Machinery; 2020:1751–1767. doi:10.1145/3372297.3423364'
apa: 'Kokoris Kogias, E., Malkhi, D., & Spiegelman, A. (2020). Asynchronous
distributed key generation for computationally-secure randomness, consensus, and
threshold signatures. In Proceedings of the 2020 ACM SIGSAC Conference on Computer
and Communications Security (pp. 1751–1767). Virtual, United States: Association
for Computing Machinery. https://doi.org/10.1145/3372297.3423364'
chicago: Kokoris Kogias, Eleftherios, Dahlia Malkhi, and Alexander Spiegelman. “Asynchronous
Distributed Key Generation for Computationally-Secure Randomness, Consensus, and
Threshold Signatures.” In Proceedings of the 2020 ACM SIGSAC Conference on
Computer and Communications Security, 1751–1767. Association for Computing
Machinery, 2020. https://doi.org/10.1145/3372297.3423364.
ieee: E. Kokoris Kogias, D. Malkhi, and A. Spiegelman, “Asynchronous distributed
key generation for computationally-secure randomness, consensus, and threshold
signatures,” in Proceedings of the 2020 ACM SIGSAC Conference on Computer and
Communications Security, Virtual, United States, 2020, pp. 1751–1767.
ista: 'Kokoris Kogias E, Malkhi D, Spiegelman A. 2020. Asynchronous distributed
key generation for computationally-secure randomness, consensus, and threshold
signatures. Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications
Security. CCS: Computer and Communications Security, 1751–1767.'
mla: Kokoris Kogias, Eleftherios, et al. “Asynchronous Distributed Key Generation
for Computationally-Secure Randomness, Consensus, and Threshold Signatures.” Proceedings
of the 2020 ACM SIGSAC Conference on Computer and Communications Security,
Association for Computing Machinery, 2020, pp. 1751–1767, doi:10.1145/3372297.3423364.
short: E. Kokoris Kogias, D. Malkhi, A. Spiegelman, in:, Proceedings of the 2020
ACM SIGSAC Conference on Computer and Communications Security, Association for
Computing Machinery, 2020, pp. 1751–1767.
conference:
end_date: 2020-11-13
location: Virtual, United States
name: 'CCS: Computer and Communications Security'
start_date: 2020-11-09
date_created: 2021-12-16T13:23:27Z
date_published: 2020-10-30T00:00:00Z
date_updated: 2024-02-22T13:10:45Z
day: '30'
department:
- _id: ElKo
doi: 10.1145/3372297.3423364
external_id:
isi:
- '000768470400104'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2019/1015
month: '10'
oa: 1
oa_version: Preprint
page: 1751–1767
publication: Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications
Security
publication_identifier:
isbn:
- 978-1-4503-7089-9
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: Asynchronous distributed key generation for computationally-secure randomness,
consensus, and threshold signatures
type: conference
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
year: '2020'
...
---
_id: '8296'
abstract:
- lang: eng
text: While showing great promise, smart contracts are difficult to program correctly,
as they need a deep understanding of cryptography and distributed algorithms,
and offer limited functionality, as they have to be deterministic and cannot operate
on secret data. In this paper we present Protean, a general-purpose decentralized
computing platform that addresses these limitations by moving from a monolithic
execution model, where all participating nodes store all the state and execute
every computation, to a modular execution-model. Protean employs secure specialized
modules, called functional units, for building decentralized applications that
are currently insecure or impossible to implement with smart contracts. Each functional
unit is a distributed system that provides a special-purpose functionality by
exposing atomic transactions to the smart-contract developer. Combining these
transactions into arbitrarily-defined workflows, developers can build a larger
class of decentralized applications, such as provably-secure and fair lotteries
or e-voting.
article_processing_charge: No
author:
- first_name: Enis Ceyhun
full_name: Alp, Enis Ceyhun
last_name: Alp
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Georgia
full_name: Fragkouli, Georgia
last_name: Fragkouli
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
citation:
ama: 'Alp EC, Kokoris Kogias E, Fragkouli G, Ford B. Rethinking general-purpose
decentralized computing. In: Proceedings of the Workshop on Hot Topics in Operating
Systems. ACM; 2019:105-112. doi:10.1145/3317550.3321448'
apa: 'Alp, E. C., Kokoris Kogias, E., Fragkouli, G., & Ford, B. (2019). Rethinking
general-purpose decentralized computing. In Proceedings of the Workshop on
Hot Topics in Operating Systems (pp. 105–112). Bertinoro, Italy: ACM. https://doi.org/10.1145/3317550.3321448'
chicago: Alp, Enis Ceyhun, Eleftherios Kokoris Kogias, Georgia Fragkouli, and Bryan
Ford. “Rethinking General-Purpose Decentralized Computing.” In Proceedings
of the Workshop on Hot Topics in Operating Systems, 105–12. ACM, 2019. https://doi.org/10.1145/3317550.3321448.
ieee: E. C. Alp, E. Kokoris Kogias, G. Fragkouli, and B. Ford, “Rethinking general-purpose
decentralized computing,” in Proceedings of the Workshop on Hot Topics in Operating
Systems, Bertinoro, Italy, 2019, pp. 105–112.
ista: 'Alp EC, Kokoris Kogias E, Fragkouli G, Ford B. 2019. Rethinking general-purpose
decentralized computing. Proceedings of the Workshop on Hot Topics in Operating
Systems. HotOS: Workshop on Hot Topics in Operating Systems, 105–112.'
mla: Alp, Enis Ceyhun, et al. “Rethinking General-Purpose Decentralized Computing.”
Proceedings of the Workshop on Hot Topics in Operating Systems, ACM, 2019,
pp. 105–12, doi:10.1145/3317550.3321448.
short: E.C. Alp, E. Kokoris Kogias, G. Fragkouli, B. Ford, in:, Proceedings of the
Workshop on Hot Topics in Operating Systems, ACM, 2019, pp. 105–112.
conference:
end_date: 2019-05-15
location: Bertinoro, Italy
name: 'HotOS: Workshop on Hot Topics in Operating Systems'
start_date: 2019-05-13
date_created: 2020-08-26T11:45:45Z
date_published: 2019-05-01T00:00:00Z
date_updated: 2021-01-12T08:17:56Z
day: '01'
doi: 10.1145/3317550.3321448
extern: '1'
language:
- iso: eng
month: '05'
oa_version: None
page: 105-112
publication: Proceedings of the Workshop on Hot Topics in Operating Systems
publication_identifier:
isbn:
- '9781450367271'
publication_status: published
publisher: ACM
quality_controlled: '1'
scopus_import: '1'
status: public
title: Rethinking general-purpose decentralized computing
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '8304'
abstract:
- lang: eng
text: "Enabling secure communication across distributed systems is usually studied
under the assumption of trust between the different systems and an external adversary
trying to compromise the messages. With the appearance of distributed ledgers
or blockchains, numerous protocols have emerged, which attempt to achieve trustless
communication between distrusting ledgers and participants. Cross-chain communication
(CCC) thereby plays a fundamental role in cryptocurrency exchanges, sharding,
bootstrapping of new and feature-extension of existing distributed ledgers. Unfortunately,
existing proposals are designed ad-hoc for specific use-cases, making it hard
to gain confidence on their correctness and composability.\r\nWe provide the first
systematic exposition of protocols for CCC. First, we formalize the underlying
research problem and show that CCC is impossible without a trusted third party,
contrary to common beliefs in the blockchain community. We then develop a framework
to evaluate existing and to design new cross-chain protocols. The framework is
based on the use case, the trust model, and the security assumptions of interlinked
blockchains. Finally, we identify security and privacy challenges faced by protocols
in the cross-chain setting.\r\nThis Systematization of Knowledge (SoK) offers
a comprehensive guide for designing protocols bridging the numerous distributed
ledgers available today. It aims to facilitate clearer communication between academia
and industry in the field."
article_number: 2019/1128
article_processing_charge: No
author:
- first_name: Alexei
full_name: Zamyatin, Alexei
last_name: Zamyatin
- first_name: Mustafa
full_name: Al-Bassam, Mustafa
last_name: Al-Bassam
- first_name: Dionysis
full_name: Zindros, Dionysis
last_name: Zindros
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Pedro
full_name: Moreno-Sanchez, Pedro
last_name: Moreno-Sanchez
- first_name: Aggelos
full_name: Kiayias, Aggelos
last_name: Kiayias
- first_name: William J.
full_name: Knottenbelt, William J.
last_name: Knottenbelt
citation:
ama: 'Zamyatin A, Al-Bassam M, Zindros D, et al. SoK: Communication across distributed
ledgers. Cryptology ePrint Archive.'
apa: 'Zamyatin, A., Al-Bassam, M., Zindros, D., Kokoris Kogias, E., Moreno-Sanchez,
P., Kiayias, A., & Knottenbelt, W. J. (n.d.). SoK: Communication across distributed
ledgers. Cryptology ePrint Archive.'
chicago: 'Zamyatin, Alexei, Mustafa Al-Bassam, Dionysis Zindros, Eleftherios Kokoris
Kogias, Pedro Moreno-Sanchez, Aggelos Kiayias, and William J. Knottenbelt. “SoK:
Communication across Distributed Ledgers.” Cryptology EPrint Archive, n.d.'
ieee: 'A. Zamyatin et al., “SoK: Communication across distributed ledgers,”
Cryptology ePrint Archive. .'
ista: 'Zamyatin A, Al-Bassam M, Zindros D, Kokoris Kogias E, Moreno-Sanchez P, Kiayias
A, Knottenbelt WJ. SoK: Communication across distributed ledgers. Cryptology ePrint
Archive, 2019/1128.'
mla: 'Zamyatin, Alexei, et al. “SoK: Communication across Distributed Ledgers.”
Cryptology EPrint Archive, 2019/1128.'
short: A. Zamyatin, M. Al-Bassam, D. Zindros, E. Kokoris Kogias, P. Moreno-Sanchez,
A. Kiayias, W.J. Knottenbelt, Cryptology EPrint Archive (n.d.).
date_created: 2020-08-26T12:16:38Z
date_published: 2019-10-01T00:00:00Z
date_updated: 2021-09-24T12:08:14Z
day: '01'
extern: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: 'https://eprint.iacr.org/2019/1128 '
month: '10'
oa: 1
oa_version: Preprint
publication: Cryptology ePrint Archive
publication_status: submitted
status: public
title: 'SoK: Communication across distributed ledgers'
type: preprint
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2019'
...
---
_id: '8303'
abstract:
- lang: eng
text: 'ByzCoin, a promising alternative of Bitcoin, is a scalable consensus protocol
used as a building block of many research and enterprise-level decentralized systems.
In this paper, we show that ByzCoin is unsuitable for deployment in an anopen,
adversarial network and instead introduceMOTOR. MOTORis designed as a secure,
robust, and scalable consensus suitable for permissionless sharded blockchains.
MOTORachieves these properties by making four key design choices: (a) it prioritizes
robustness in adversarial environments while maintaining adequate scalability,
(b) it employees provably correct cryptography that resists DoS attacks from individual
nodes, (c) it deploys unpredictable rotating leaders to defend against mildly-adaptive
adversaries and prevents censorship, and (d) it creates an incentive compatible
reward mechanism. These choices are materialized as (a) a “rotating subleader”
communication pattern that balances the scalability needs with the robustness
requirements under failures, (b) deployment of provable secure BLS multi-signatures,
(c) use of deterministic thresh-old signatures as a source of randomness and (d)
careful design of the reward allocation mechanism. We have implemented MOTORand
compare it withByzCoin. We show that MOTORcan scale similar to ByzCoin with an
at most2xoverhead whereas it maintains good performance even under high-percentage
of faults, unlike ByzCoin.'
article_number: 2019/676
article_processing_charge: No
author:
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
citation:
ama: Kokoris Kogias E. Robust and scalable consensus for sharded distributed ledgers.
Cryptology ePrint Archive.
apa: Kokoris Kogias, E. (n.d.). Robust and scalable consensus for sharded distributed
ledgers. Cryptology ePrint Archive.
chicago: Kokoris Kogias, Eleftherios. “Robust and Scalable Consensus for Sharded
Distributed Ledgers.” Cryptology EPrint Archive, n.d.
ieee: E. Kokoris Kogias, “Robust and scalable consensus for sharded distributed
ledgers,” Cryptology ePrint Archive. .
ista: Kokoris Kogias E. Robust and scalable consensus for sharded distributed ledgers.
Cryptology ePrint Archive, 2019/676.
mla: Kokoris Kogias, Eleftherios. “Robust and Scalable Consensus for Sharded Distributed
Ledgers.” Cryptology EPrint Archive, 2019/676.
short: E. Kokoris Kogias, Cryptology EPrint Archive (n.d.).
date_created: 2020-08-26T12:13:56Z
date_published: 2019-06-06T00:00:00Z
date_updated: 2021-09-24T12:07:11Z
day: '06'
extern: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2019/676
month: '06'
oa: 1
oa_version: Preprint
publication: Cryptology ePrint Archive
publication_status: submitted
status: public
title: Robust and scalable consensus for sharded distributed ledgers
type: preprint
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2019'
...
---
_id: '8311'
abstract:
- lang: eng
text: 'One of the core promises of blockchain technology is that of enabling trustworthy
data dissemination in a trustless environment. What current blockchain systems
deliver, however, is slow dissemination of public data, rendering blockchain technology
unusable in settings where latency, transaction capacity, or data confidentiality
are important. In this thesis we focus on providing solutions on two of the most
pressing problems blockchain technology currently faces: scalability and data
confidentiality. To address the scalability issue, we present OMNILEDGER, a novel
scale-out distributed ledger that preserves long-term security under permissionless
operation. It ensures security and correctness by using a bias-resistant public-randomness
protocol for choosing large, statistically representative shards that process
transactions, and by introducing an efficient cross-shard commit protocol that
atomically handles transactions affecting multiple shards. To enable secure sharing
of confidential data we present CALYPSO, the first fully decentralized, auditable
access-control framework for secure blockchain-based data sharing which builds
upon two abstractions. First, on-chain secrets enable collective management of
(verifiably shared) secrets under a Byzantine adversary where an access-control
blockchain enforces user-specific access rules and a secret-management cothority
administers encrypted data. Second, skipchain-based identity and access management
enables efficient administration of dynamic, sovereign identities and access policies
and, in particular, permits clients to maintain long-term relationships with respect
to evolving user identities thanks to the trust-delegating forward links of skipchains.
In order to build OMNILEDGER and CALYPSO, we first build a set of tools for efficient
decentralization, which are presented in Part II of this dissertation. These tools
can be used in decentralized and distributed systems to achieve (1) scalable consensus
(BYZCOIN), (2) bias- resistant distributed randomness creations (RANDHOUND), and
(3) relationship-keeping between independently updating communication endpoints
(SKIPCHAINIAC). Although we use this tools in the scope off this thesis, they
can be (and already have been) used in a far wider scope.'
article_processing_charge: No
author:
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
citation:
ama: Kokoris Kogias E. Secure, confidential blockchains providing high throughput
and low latency. 2019. doi:10.5075/epfl-thesis-7101
apa: Kokoris Kogias, E. (2019). Secure, confidential blockchains providing high
throughput and low latency. École Polytechnique Fédérale de Lausanne. https://doi.org/10.5075/epfl-thesis-7101
chicago: Kokoris Kogias, Eleftherios. “Secure, Confidential Blockchains Providing
High Throughput and Low Latency.” École Polytechnique Fédérale de Lausanne, 2019.
https://doi.org/10.5075/epfl-thesis-7101.
ieee: E. Kokoris Kogias, “Secure, confidential blockchains providing high throughput
and low latency,” École Polytechnique Fédérale de Lausanne, 2019.
ista: Kokoris Kogias E. 2019. Secure, confidential blockchains providing high throughput
and low latency. École Polytechnique Fédérale de Lausanne.
mla: Kokoris Kogias, Eleftherios. Secure, Confidential Blockchains Providing
High Throughput and Low Latency. École Polytechnique Fédérale de Lausanne,
2019, doi:10.5075/epfl-thesis-7101.
short: E. Kokoris Kogias, Secure, Confidential Blockchains Providing High Throughput
and Low Latency, École Polytechnique Fédérale de Lausanne, 2019.
date_created: 2020-08-27T11:22:24Z
date_published: 2019-09-27T00:00:00Z
date_updated: 2021-12-20T15:30:47Z
day: '27'
degree_awarded: PhD
doi: 10.5075/epfl-thesis-7101
extern: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://www.doi.org/10.5075/epfl-thesis-7101
month: '09'
oa: 1
oa_version: Published Version
page: '244'
publication_status: published
publisher: École Polytechnique Fédérale de Lausanne
status: public
supervisor:
- first_name: Bryan Alexander
full_name: Ford, Bryan Alexander
last_name: Ford
title: Secure, confidential blockchains providing high throughput and low latency
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2019'
...
---
_id: '8314'
abstract:
- lang: eng
text: "Off-chain protocols (channels) are a promising solution to the scalability
and privacy challenges of blockchain payments. Current proposals, however, require
synchrony assumptions to preserve the safety of a channel, leaking to an adversary
the exact amount of time needed to control the network for a successful attack.
In this paper, we introduce Brick, the first payment channel that remains secure
under network asynchrony and concurrently provides correct incentives. The core
idea is to incorporate the conflict resolution process within the channel by introducing
a rational committee of external parties, called Wardens. Hence, if a party wants
to close a channel unilaterally, it can only get the committee's approval for
the last valid state. Brick provides sub-second latency because it does not employ
heavy-weight consensus. Instead,\r\nBrick uses consistent broadcast to announce
updates and close the channel, a light-weight abstraction that is powerful enough
to preserve safety and liveness to any rational parties. Furthermore, we consider
permissioned blockchains, where the additional property of auditability might
be desired for regulatory purposes. We introduce Brick+, an off-chain construction
that provides auditability on top of Brick without conflicting with its privacy
guarantees. We formally define the properties our payment channel construction
should fulfill, and prove that both Brick and Brick+ satisfy them. We also design
incentives for Brick such that honest and rational behavior aligns. Finally, we
provide a reference implementation of the smart contracts in Solidity."
article_number: '1905.11360'
article_processing_charge: No
author:
- first_name: Georgia
full_name: Avarikioti, Georgia
last_name: Avarikioti
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Roger
full_name: Wattenhofer, Roger
last_name: Wattenhofer
- first_name: Dionysis
full_name: Zindros, Dionysis
last_name: Zindros
citation:
ama: 'Avarikioti G, Kokoris Kogias E, Wattenhofer R, Zindros D. Brick: Asynchronous
payment channels. arXiv.'
apa: 'Avarikioti, G., Kokoris Kogias, E., Wattenhofer, R., & Zindros, D. (n.d.).
Brick: Asynchronous payment channels. arXiv.'
chicago: 'Avarikioti, Georgia, Eleftherios Kokoris Kogias, Roger Wattenhofer, and
Dionysis Zindros. “Brick: Asynchronous Payment Channels.” ArXiv, n.d.'
ieee: 'G. Avarikioti, E. Kokoris Kogias, R. Wattenhofer, and D. Zindros, “Brick:
Asynchronous payment channels,” arXiv. .'
ista: 'Avarikioti G, Kokoris Kogias E, Wattenhofer R, Zindros D. Brick: Asynchronous
payment channels. arXiv, 1905.11360.'
mla: 'Avarikioti, Georgia, et al. “Brick: Asynchronous Payment Channels.” ArXiv,
1905.11360.'
short: G. Avarikioti, E. Kokoris Kogias, R. Wattenhofer, D. Zindros, ArXiv (n.d.).
date_created: 2020-08-27T11:36:54Z
date_published: 2019-05-27T00:00:00Z
date_updated: 2021-01-12T08:18:04Z
day: '27'
extern: '1'
external_id:
arxiv:
- '1905.11360'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1905.11360
month: '05'
oa: 1
oa_version: Preprint
publication: arXiv
publication_status: submitted
status: public
title: 'Brick: Asynchronous payment channels'
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '8315'
abstract:
- lang: eng
text: "Sharding distributed ledgers is the most promising on-chain solution for
scaling blockchain technology. In this work, we define and analyze the properties
a sharded distributed ledger should fulfill. More specifically, we show that a
sharded blockchain cannot be scalable under a fully adaptive adversary, but it
can scale up to $O(n/\\log n)$ under an epoch-adaptive adversary. This is possible
only if the distributed ledger creates succinct proofs of the valid state updates
at the end of each epoch. Our model builds upon and extends the Bitcoin backbone
protocol by defining consistency and\r\nscalability. Consistency encompasses the
need for atomic execution of cross-shard transactions to preserve safety, whereas
scalability encapsulates the speedup a sharded system can gain in comparison to
a non-sharded system. In\r\norder to show the power of our framework, we analyze
the most prominent sharded blockchains and either prove their correctness (OmniLedger,
RapidChain) under our model or pinpoint where they fail to balance the consistency
and\r\nscalability requirements (Elastico, Monoxide). "
article_number: '1910.10434'
article_processing_charge: No
author:
- first_name: Georgia
full_name: Avarikioti, Georgia
last_name: Avarikioti
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Roger
full_name: Wattenhofer, Roger
last_name: Wattenhofer
citation:
ama: 'Avarikioti G, Kokoris Kogias E, Wattenhofer R. Divide and scale: Formalization
of distributed ledger sharding protocols. arXiv.'
apa: 'Avarikioti, G., Kokoris Kogias, E., & Wattenhofer, R. (n.d.). Divide and
scale: Formalization of distributed ledger sharding protocols. arXiv.'
chicago: 'Avarikioti, Georgia, Eleftherios Kokoris Kogias, and Roger Wattenhofer.
“Divide and Scale: Formalization of Distributed Ledger Sharding Protocols.” ArXiv,
n.d.'
ieee: 'G. Avarikioti, E. Kokoris Kogias, and R. Wattenhofer, “Divide and scale:
Formalization of distributed ledger sharding protocols,” arXiv. .'
ista: 'Avarikioti G, Kokoris Kogias E, Wattenhofer R. Divide and scale: Formalization
of distributed ledger sharding protocols. arXiv, 1910.10434.'
mla: 'Avarikioti, Georgia, et al. “Divide and Scale: Formalization of Distributed
Ledger Sharding Protocols.” ArXiv, 1910.10434.'
short: G. Avarikioti, E. Kokoris Kogias, R. Wattenhofer, ArXiv (n.d.).
date_created: 2020-08-27T11:37:43Z
date_published: 2019-10-23T00:00:00Z
date_updated: 2021-01-12T08:18:05Z
day: '23'
extern: '1'
external_id:
arxiv:
- '1910.10434'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1910.10434
month: '10'
oa: 1
oa_version: Preprint
publication: arXiv
publication_status: submitted
status: public
title: 'Divide and scale: Formalization of distributed ledger sharding protocols'
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '8313'
abstract:
- lang: eng
text: The present invention concerns a computer-implemented method for secure data
exchange between a sender (A) and a recipient (B), wherein the method is performed
by the sender (A) and comprises encrypting data using a symmetric key k, creating
a write transaction T W , wherein the write transaction T W comprises information
usable to derive the symmetric key k and an access policy identifying the recipient
(B) as being allowed to decrypt the encrypted data, providing the recipient (B)
access to the encrypted data, and sending the write transaction T W to a first
group of servers (AC) for being stored in a blockchain data structure maintained
by the first group of servers (AC).
applicant:
- 'École Polytechnique Fédérale De Lausanne '
article_processing_charge: No
author:
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
- first_name: Linus
full_name: Gasser, Linus
last_name: Gasser
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Philipp
full_name: Janovic, Philipp
last_name: Janovic
citation:
ama: Ford B, Gasser L, Kokoris Kogias E, Janovic P. Methods and systems for secure
data exchange. 2019.
apa: Ford, B., Gasser, L., Kokoris Kogias, E., & Janovic, P. (2019). Methods
and systems for secure data exchange.
chicago: Ford, Bryan, Linus Gasser, Eleftherios Kokoris Kogias, and Philipp Janovic.
“Methods and Systems for Secure Data Exchange,” 2019.
ieee: B. Ford, L. Gasser, E. Kokoris Kogias, and P. Janovic, “Methods and systems
for secure data exchange.” 2019.
ista: Ford B, Gasser L, Kokoris Kogias E, Janovic P. 2019. Methods and systems for
secure data exchange.
mla: Ford, Bryan, et al. Methods and Systems for Secure Data Exchange. 2019.
short: B. Ford, L. Gasser, E. Kokoris Kogias, P. Janovic, (2019).
date_created: 2020-08-27T11:24:44Z
date_published: 2019-08-22T00:00:00Z
date_updated: 2022-01-05T14:00:32Z
day: '22'
extern: '1'
ipc: G06F21/62 ; H04L9/08 ; H04L9/32
ipn: WO2019158209 (A1)
main_file_link:
- open_access: '1'
url: https://patents.google.com/patent/WO2019158209A1
month: '08'
oa: 1
oa_version: Published Version
publication_date: 2019-08-22
status: public
title: Methods and systems for secure data exchange
type: patent
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2019'
...
---
_id: '8305'
abstract:
- lang: eng
text: In this paper, we present the first fully asynchronous distributed key generation
(ADKG) algorithm as well as the first distributed key generation algorithm that
can create keys with a dual (f,2f+1)−threshold that are necessary for scalable
consensus (which so far needs a trusted dealer assumption). In order to create
a DKG with a dual (f,2f+1)− threshold we first answer in the affirmative the open
question posed by Cachin et al. how to create an AVSS protocol with recovery thresholds
f+1Cryptology
ePrint Archive.'
apa: 'Kokoris Kogias, E., Spiegelman, A., Malkhi, D., & Abraham, I. (n.d.).
Bootstrapping consensus without trusted setup: fully asynchronous distributed
key generation. Cryptology ePrint Archive.'
chicago: 'Kokoris Kogias, Eleftherios, Alexander Spiegelman, Dahlia Malkhi, and
Ittai Abraham. “Bootstrapping Consensus without Trusted Setup: Fully Asynchronous
Distributed Key Generation.” Cryptology EPrint Archive, n.d.'
ieee: 'E. Kokoris Kogias, A. Spiegelman, D. Malkhi, and I. Abraham, “Bootstrapping
consensus without trusted setup: fully asynchronous distributed key generation,”
Cryptology ePrint Archive. .'
ista: 'Kokoris Kogias E, Spiegelman A, Malkhi D, Abraham I. Bootstrapping consensus
without trusted setup: fully asynchronous distributed key generation. Cryptology
ePrint Archive, 2019/1015.'
mla: 'Kokoris Kogias, Eleftherios, et al. “Bootstrapping Consensus without Trusted
Setup: Fully Asynchronous Distributed Key Generation.” Cryptology EPrint Archive,
2019/1015.'
short: E. Kokoris Kogias, A. Spiegelman, D. Malkhi, I. Abraham, Cryptology EPrint
Archive (n.d.).
date_created: 2020-08-26T12:18:00Z
date_published: 2019-09-10T00:00:00Z
date_updated: 2023-05-10T09:27:54Z
day: '10'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2019/1015
month: '09'
oa: 1
oa_version: Preprint
publication: Cryptology ePrint Archive
publication_status: submitted
status: public
title: 'Bootstrapping consensus without trusted setup: fully asynchronous distributed
key generation'
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '8298'
abstract:
- lang: eng
text: Sharding, or partitioning the system’s state so that different subsets of
participants handle it, is a proven approach to building distributed systems whose
total capacity scales horizontally with the number of participants. Many distributed
ledgers have adopted this approach to increase their performance, however, they
focus on the permissionless setting that assumes the existence of a strong adversary.
In this paper, we deploy channels for permissioned blockchains. Our first contribution
is to adapt sharding on asset-management applications for the permissioned setting,
while preserving liveness and safety even on transactions spanning across-channels.
Our second contribution is to leverage channels as a confidentiality boundary,
enabling different organizations and consortia to preserve their privacy within
their channels and still be part of a bigger collaborative ecosystem. To make
our system concrete we map it on top of Hyperledger Fabric.
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Elli
full_name: Androulaki, Elli
last_name: Androulaki
- first_name: Christian
full_name: Cachin, Christian
last_name: Cachin
- first_name: Angelo
full_name: De Caro, Angelo
last_name: De Caro
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
citation:
ama: 'Androulaki E, Cachin C, De Caro A, Kokoris Kogias E. Channels: Horizontal
scaling and confidentiality on permissioned blockchains. In: Computer Security.
Vol 11098. Springer Nature; 2018:111-131. doi:10.1007/978-3-319-99073-6_6'
apa: 'Androulaki, E., Cachin, C., De Caro, A., & Kokoris Kogias, E. (2018).
Channels: Horizontal scaling and confidentiality on permissioned blockchains.
In Computer Security (Vol. 11098, pp. 111–131). Barcelona, Spain: Springer
Nature. https://doi.org/10.1007/978-3-319-99073-6_6'
chicago: 'Androulaki, Elli, Christian Cachin, Angelo De Caro, and Eleftherios Kokoris
Kogias. “Channels: Horizontal Scaling and Confidentiality on Permissioned Blockchains.”
In Computer Security, 11098:111–31. Springer Nature, 2018. https://doi.org/10.1007/978-3-319-99073-6_6.'
ieee: 'E. Androulaki, C. Cachin, A. De Caro, and E. Kokoris Kogias, “Channels: Horizontal
scaling and confidentiality on permissioned blockchains,” in Computer Security,
Barcelona, Spain, 2018, vol. 11098, pp. 111–131.'
ista: 'Androulaki E, Cachin C, De Caro A, Kokoris Kogias E. 2018. Channels: Horizontal
scaling and confidentiality on permissioned blockchains. Computer Security. ESORICS:
European Symposium on Research in Computer Security, LNCS, vol. 11098, 111–131.'
mla: 'Androulaki, Elli, et al. “Channels: Horizontal Scaling and Confidentiality
on Permissioned Blockchains.” Computer Security, vol. 11098, Springer Nature,
2018, pp. 111–31, doi:10.1007/978-3-319-99073-6_6.'
short: E. Androulaki, C. Cachin, A. De Caro, E. Kokoris Kogias, in:, Computer Security,
Springer Nature, 2018, pp. 111–131.
conference:
end_date: 2018-09-07
location: Barcelona, Spain
name: 'ESORICS: European Symposium on Research in Computer Security'
start_date: 2018-09-03
date_created: 2020-08-26T11:47:34Z
date_published: 2018-08-08T00:00:00Z
date_updated: 2021-01-12T08:17:57Z
day: '08'
doi: 10.1007/978-3-319-99073-6_6
extern: '1'
intvolume: ' 11098'
language:
- iso: eng
month: '08'
oa_version: None
page: 111-131
publication: Computer Security
publication_identifier:
eisbn:
- '9783319990736'
isbn:
- '9783319990729'
issn:
- 0302-9743
- 1611-3349
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
status: public
title: 'Channels: Horizontal scaling and confidentiality on permissioned blockchains'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 11098
year: '2018'
...
---
_id: '8297'
abstract:
- lang: eng
text: "Designing a secure permissionless distributed ledger (blockchain) that performs
on par with centralized payment\r\nprocessors, such as Visa, is a challenging
task. Most existing distributed ledgers are unable to scale-out, i.e., to grow
their totalprocessing capacity with the number of validators; and those that do,
compromise security or decentralization. We present OmniLedger, a novel scale-out
distributed ledger that preserves longterm security under permissionless operation.
It ensures security and correctness by using a bias-resistant public-randomness
protocol for choosing large, statistically representative shards that process
transactions, and by introducing an efficient crossshard commit protocol that
atomically handles transactions affecting multiple shards. OmniLedger also optimizes
performance via parallel intra-shard transaction processing, ledger pruning via
collectively-signed state blocks, and low-latency “trust-butverify” \r\nvalidation
for low-value transactions. An evaluation ofour experimental prototype shows that
OmniLedger’s throughput\r\nscales linearly in the number of active validators,
supporting Visa-level workloads and beyond, while confirming typical transactions
in under two seconds."
article_processing_charge: No
author:
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Philipp
full_name: Jovanovic, Philipp
last_name: Jovanovic
- first_name: Linus
full_name: Gasser, Linus
last_name: Gasser
- first_name: Nicolas
full_name: Gailly, Nicolas
last_name: Gailly
- first_name: Ewa
full_name: Syta, Ewa
last_name: Syta
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
citation:
ama: 'Kokoris Kogias E, Jovanovic P, Gasser L, Gailly N, Syta E, Ford B. OmniLedger:
A secure, scale-out, decentralized ledger via sharding. In: 2018 IEEE Symposium
on Security and Privacy. IEEE; 2018:583-598. doi:10.1109/sp.2018.000-5'
apa: 'Kokoris Kogias, E., Jovanovic, P., Gasser, L., Gailly, N., Syta, E., &
Ford, B. (2018). OmniLedger: A secure, scale-out, decentralized ledger via sharding.
In 2018 IEEE Symposium on Security and Privacy (pp. 583–598). San Francisco,
CA, United States: IEEE. https://doi.org/10.1109/sp.2018.000-5'
chicago: 'Kokoris Kogias, Eleftherios, Philipp Jovanovic, Linus Gasser, Nicolas
Gailly, Ewa Syta, and Bryan Ford. “OmniLedger: A Secure, Scale-out, Decentralized
Ledger via Sharding.” In 2018 IEEE Symposium on Security and Privacy, 583–98.
IEEE, 2018. https://doi.org/10.1109/sp.2018.000-5.'
ieee: 'E. Kokoris Kogias, P. Jovanovic, L. Gasser, N. Gailly, E. Syta, and B. Ford,
“OmniLedger: A secure, scale-out, decentralized ledger via sharding,” in 2018
IEEE Symposium on Security and Privacy, San Francisco, CA, United States,
2018, pp. 583–598.'
ista: 'Kokoris Kogias E, Jovanovic P, Gasser L, Gailly N, Syta E, Ford B. 2018.
OmniLedger: A secure, scale-out, decentralized ledger via sharding. 2018 IEEE
Symposium on Security and Privacy. SP: Symposium on Security and Privacy, 583–598.'
mla: 'Kokoris Kogias, Eleftherios, et al. “OmniLedger: A Secure, Scale-out, Decentralized
Ledger via Sharding.” 2018 IEEE Symposium on Security and Privacy, IEEE,
2018, pp. 583–98, doi:10.1109/sp.2018.000-5.'
short: E. Kokoris Kogias, P. Jovanovic, L. Gasser, N. Gailly, E. Syta, B. Ford,
in:, 2018 IEEE Symposium on Security and Privacy, IEEE, 2018, pp. 583–598.
conference:
end_date: 2018-05-24
location: San Francisco, CA, United States
name: 'SP: Symposium on Security and Privacy'
start_date: 2018-05-20
date_created: 2020-08-26T11:46:35Z
date_published: 2018-07-26T00:00:00Z
date_updated: 2021-01-12T08:17:56Z
day: '26'
doi: 10.1109/sp.2018.000-5
extern: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2017/406
month: '07'
oa: 1
oa_version: Preprint
page: 583-598
publication: 2018 IEEE Symposium on Security and Privacy
publication_identifier:
isbn:
- '9781538643532'
issn:
- 2375-1207
publication_status: published
publisher: IEEE
quality_controlled: '1'
status: public
title: 'OmniLedger: A secure, scale-out, decentralized ledger via sharding'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2018'
...
---
_id: '8299'
abstract:
- lang: eng
text: 'Permissionless blockchain-based cryptocurrencies commonly use proof-of-work
(PoW) or proof-of-stake (PoS) to ensure their security, e.g. to prevent double
spending attacks. However, both approaches have disadvantages: PoW leads to massive
amounts of wasted electricity and re-centralization, whereas major stakeholders
in PoS might be able to create a monopoly. In this work, we propose proof-of-personhood
(PoP), a mechanism that binds physical entities to virtual identities in a way
that enables accountability while preserving anonymity. Afterwards we introduce
PoPCoin, a new cryptocurrency, whose consensus mechanism leverages PoP to eliminate
the dis-advantages of PoW and PoS while ensuring security. PoPCoin leads to a
continuously fair and democratic wealth creation process which paves the way for
an experimental basic income infrastructure.'
article_number: '7966966'
article_processing_charge: No
author:
- first_name: Maria
full_name: Borge, Maria
last_name: Borge
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Philipp
full_name: Jovanovic, Philipp
last_name: Jovanovic
- first_name: Linus
full_name: Gasser, Linus
last_name: Gasser
- first_name: Nicolas
full_name: Gailly, Nicolas
last_name: Gailly
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
citation:
ama: 'Borge M, Kokoris Kogias E, Jovanovic P, Gasser L, Gailly N, Ford B. Proof-of-personhood:
Redemocratizing permissionless cryptocurrencies. In: 2017 IEEE European Symposium
on Security and Privacy Workshops. IEEE; 2017. doi:10.1109/eurospw.2017.46'
apa: 'Borge, M., Kokoris Kogias, E., Jovanovic, P., Gasser, L., Gailly, N., &
Ford, B. (2017). Proof-of-personhood: Redemocratizing permissionless cryptocurrencies.
In 2017 IEEE European Symposium on Security and Privacy Workshops. Paris,
France: IEEE. https://doi.org/10.1109/eurospw.2017.46'
chicago: 'Borge, Maria, Eleftherios Kokoris Kogias, Philipp Jovanovic, Linus Gasser,
Nicolas Gailly, and Bryan Ford. “Proof-of-Personhood: Redemocratizing Permissionless
Cryptocurrencies.” In 2017 IEEE European Symposium on Security and Privacy
Workshops. IEEE, 2017. https://doi.org/10.1109/eurospw.2017.46.'
ieee: 'M. Borge, E. Kokoris Kogias, P. Jovanovic, L. Gasser, N. Gailly, and B. Ford,
“Proof-of-personhood: Redemocratizing permissionless cryptocurrencies,” in 2017
IEEE European Symposium on Security and Privacy Workshops, Paris, France,
2017.'
ista: 'Borge M, Kokoris Kogias E, Jovanovic P, Gasser L, Gailly N, Ford B. 2017.
Proof-of-personhood: Redemocratizing permissionless cryptocurrencies. 2017 IEEE
European Symposium on Security and Privacy Workshops. EuroS&PW: European Symposium
on Security and Privacy Workshops, 7966966.'
mla: 'Borge, Maria, et al. “Proof-of-Personhood: Redemocratizing Permissionless
Cryptocurrencies.” 2017 IEEE European Symposium on Security and Privacy Workshops,
7966966, IEEE, 2017, doi:10.1109/eurospw.2017.46.'
short: M. Borge, E. Kokoris Kogias, P. Jovanovic, L. Gasser, N. Gailly, B. Ford,
in:, 2017 IEEE European Symposium on Security and Privacy Workshops, IEEE, 2017.
conference:
end_date: 2017-04-28
location: Paris, France
name: 'EuroS&PW: European Symposium on Security and Privacy Workshops'
start_date: 2017-04-26
date_created: 2020-08-26T11:48:11Z
date_published: 2017-06-30T00:00:00Z
date_updated: 2021-01-12T08:17:57Z
day: '30'
doi: 10.1109/eurospw.2017.46
extern: '1'
language:
- iso: eng
month: '06'
oa_version: None
publication: 2017 IEEE European Symposium on Security and Privacy Workshops
publication_identifier:
eisbn:
- '9781538622445'
publication_status: published
publisher: IEEE
quality_controlled: '1'
status: public
title: 'Proof-of-personhood: Redemocratizing permissionless cryptocurrencies'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2017'
...
---
_id: '8306'
abstract:
- lang: eng
text: Bias-resistant public randomness is a critical component in many (distributed)
protocols. Generating public randomness is hard, however, because active adversaries
may behave dishonestly to bias public random choices toward their advantage. Existing
solutions do not scale to hundreds or thousands of participants, as is needed
in many decentralized systems. We propose two large-scale distributed protocols,
RandHound and RandHerd, which provide publicly-verifiable, unpredictable, and
unbiasable randomness against Byzantine adversaries. RandHound relies on an untrusted
client to divide a set of randomness servers into groups for scalability, and
it depends on the pigeonhole principle to ensure output integrity, even for non-random,
adversarial group choices. RandHerd implements an efficient, decentralized randomness
beacon. RandHerd is structurally similar to a BFT protocol, but uses RandHound
in a one-time setup to arrange participants into verifiably unbiased random secret-sharing
groups, which then repeatedly produce random output at predefined intervals. Our
prototype demonstrates that RandHound and RandHerd achieve good performance across
hundreds of participants while retaining a low failure probability by properly
selecting protocol parameters, such as a group size and secret-sharing threshold.
For example, when sharding 512 nodes into groups of 32, our experiments show that
RandHound can produce fresh random output after 240 seconds. RandHerd, after a
setup phase of 260 seconds, is able to generate fresh random output in intervals
of approximately 6 seconds. For this configuration, both protocols operate at
a failure probability of at most 0.08% against a Byzantine adversary.
article_processing_charge: No
author:
- first_name: E.
full_name: Syta, E.
last_name: Syta
- first_name: P.
full_name: Jovanovic, P.
last_name: Jovanovic
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: N.
full_name: Gailly, N.
last_name: Gailly
- first_name: L.
full_name: Gasser, L.
last_name: Gasser
- first_name: I.
full_name: Khoffi, I.
last_name: Khoffi
- first_name: M. J.
full_name: Fischer, M. J.
last_name: Fischer
- first_name: B.
full_name: Ford, B.
last_name: Ford
citation:
ama: 'Syta E, Jovanovic P, Kokoris Kogias E, et al. Scalable bias-resistant distributed
randomness. In: 2017 IEEE Symposium on Security and Privacy. IEEE; 2017:444-460.
doi:10.1109/SP.2017.45'
apa: 'Syta, E., Jovanovic, P., Kokoris Kogias, E., Gailly, N., Gasser, L., Khoffi,
I., … Ford, B. (2017). Scalable bias-resistant distributed randomness. In 2017
IEEE Symposium on Security and Privacy (pp. 444–460). San Jose, CA, United
States: IEEE. https://doi.org/10.1109/SP.2017.45'
chicago: Syta, E., P. Jovanovic, Eleftherios Kokoris Kogias, N. Gailly, L. Gasser,
I. Khoffi, M. J. Fischer, and B. Ford. “Scalable Bias-Resistant Distributed Randomness.”
In 2017 IEEE Symposium on Security and Privacy, 444–60. IEEE, 2017. https://doi.org/10.1109/SP.2017.45.
ieee: E. Syta et al., “Scalable bias-resistant distributed randomness,” in
2017 IEEE Symposium on Security and Privacy, San Jose, CA, United States,
2017, pp. 444–460.
ista: 'Syta E, Jovanovic P, Kokoris Kogias E, Gailly N, Gasser L, Khoffi I, Fischer
MJ, Ford B. 2017. Scalable bias-resistant distributed randomness. 2017 IEEE Symposium
on Security and Privacy. SP: Symposium on Security and Privacy, 444–460.'
mla: Syta, E., et al. “Scalable Bias-Resistant Distributed Randomness.” 2017
IEEE Symposium on Security and Privacy, IEEE, 2017, pp. 444–60, doi:10.1109/SP.2017.45.
short: E. Syta, P. Jovanovic, E. Kokoris Kogias, N. Gailly, L. Gasser, I. Khoffi,
M.J. Fischer, B. Ford, in:, 2017 IEEE Symposium on Security and Privacy, IEEE,
2017, pp. 444–460.
conference:
end_date: 2017-05-26
location: San Jose, CA, United States
name: 'SP: Symposium on Security and Privacy'
start_date: 2017-05-22
date_created: 2020-08-26T12:26:08Z
date_published: 2017-06-01T00:00:00Z
date_updated: 2021-01-12T08:18:02Z
day: '01'
doi: 10.1109/SP.2017.45
extern: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2016/1067
month: '06'
oa: 1
oa_version: Preprint
page: 444-460
publication: 2017 IEEE Symposium on Security and Privacy
publication_identifier:
isbn:
- '9781509055340'
issn:
- 2375-1207
publication_status: published
publisher: IEEE
quality_controlled: '1'
status: public
title: Scalable bias-resistant distributed randomness
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2017'
...
---
_id: '8301'
abstract:
- lang: eng
text: Software-update mechanisms are critical to the security of modern systems,
but their typically centralized design presents a lucrative and frequently attacked
target. In this work, we propose CHAINIAC, a decentralized software-update framework
that eliminates single points of failure, enforces transparency, and provides
efficient verifiability of integrity and authenticity for software-release processes.
Independent witness servers collectively verify conformance of software updates
to release policies, build verifiers validate the source-to-binary correspondence,
and a tamper-proof release log stores collectively signed updates, thus ensuring
that no release is accepted by clients before being widely disclosed and validated.
The release log embodies a skipchain, a novel data structure, enabling arbitrarily
out-of-date clients to efficiently validate updates and signing keys. Evaluation
of our CHAINIAC prototype on reproducible Debian packages shows that the automated
update process takes the average of 5 minutes per release for individual packages,
and only 20 seconds for the aggregate timeline. We further evaluate the framework
using real-world data from the PyPI package repository and show that it offers
clients security comparable to verifying every single update themselves while
consuming only one-fifth of the bandwidth and having a minimal computational overhead.
article_processing_charge: No
author:
- first_name: Kirill
full_name: Nikitin, Kirill
last_name: Nikitin
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Philipp
full_name: Jovanovic, Philipp
last_name: Jovanovic
- first_name: Linus
full_name: Gasser, Linus
last_name: Gasser
- first_name: Nicolas
full_name: Gailly, Nicolas
last_name: Gailly
- first_name: Ismail
full_name: Khoffi, Ismail
last_name: Khoffi
- first_name: Justin
full_name: Cappos, Justin
last_name: Cappos
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
citation:
ama: 'Nikitin K, Kokoris Kogias E, Jovanovic P, et al. CHAINIAC: Proactive software-update
transparency via collectively signed skipchains and verified builds. In: Proceedings
of the 26th USENIX Conference on Security Symposium. USENIX Association; 2017:1271–1287.'
apa: 'Nikitin, K., Kokoris Kogias, E., Jovanovic, P., Gasser, L., Gailly, N., Khoffi,
I., … Ford, B. (2017). CHAINIAC: Proactive software-update transparency via collectively
signed skipchains and verified builds. In Proceedings of the 26th USENIX Conference
on Security Symposium (pp. 1271–1287). Vancouver, Canada: USENIX Association.'
chicago: 'Nikitin, Kirill, Eleftherios Kokoris Kogias, Philipp Jovanovic, Linus
Gasser, Nicolas Gailly, Ismail Khoffi, Justin Cappos, and Bryan Ford. “CHAINIAC:
Proactive Software-Update Transparency via Collectively Signed Skipchains and
Verified Builds.” In Proceedings of the 26th USENIX Conference on Security
Symposium, 1271–1287. USENIX Association, 2017.'
ieee: 'K. Nikitin et al., “CHAINIAC: Proactive software-update transparency
via collectively signed skipchains and verified builds,” in Proceedings of
the 26th USENIX Conference on Security Symposium, Vancouver, Canada, 2017,
pp. 1271–1287.'
ista: 'Nikitin K, Kokoris Kogias E, Jovanovic P, Gasser L, Gailly N, Khoffi I, Cappos
J, Ford B. 2017. CHAINIAC: Proactive software-update transparency via collectively
signed skipchains and verified builds. Proceedings of the 26th USENIX Conference
on Security Symposium. SEC: Security Symposium, 1271–1287.'
mla: 'Nikitin, Kirill, et al. “CHAINIAC: Proactive Software-Update Transparency
via Collectively Signed Skipchains and Verified Builds.” Proceedings of the
26th USENIX Conference on Security Symposium, USENIX Association, 2017, pp.
1271–1287.'
short: K. Nikitin, E. Kokoris Kogias, P. Jovanovic, L. Gasser, N. Gailly, I. Khoffi,
J. Cappos, B. Ford, in:, Proceedings of the 26th USENIX Conference on Security
Symposium, USENIX Association, 2017, pp. 1271–1287.
conference:
end_date: 2017-08-18
location: Vancouver, Canada
name: 'SEC: Security Symposium'
start_date: 2017-08-16
date_created: 2020-08-26T12:04:44Z
date_published: 2017-09-01T00:00:00Z
date_updated: 2021-01-12T08:18:00Z
day: '01'
extern: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://www.usenix.org/system/files/conference/usenixsecurity17/sec17-nikitin.pdf
month: '09'
oa: 1
oa_version: Published Version
page: 1271–1287
publication: Proceedings of the 26th USENIX Conference on Security Symposium
publication_identifier:
isbn:
- '9781931971409'
publication_status: published
publisher: USENIX Association
quality_controlled: '1'
status: public
title: 'CHAINIAC: Proactive software-update transparency via collectively signed skipchains
and verified builds'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2017'
...
---
_id: '8302'
abstract:
- lang: eng
text: While showing great promise, Bitcoin requires users to wait tens of minutes
for transactions to commit, and even then, offering only probabilistic guarantees.
This paper introduces ByzCoin, a novel Byzantine consensus protocol that leverages
scalable collective signing to commit Bitcoin transactions irreversibly within
seconds. ByzCoin achieves Byzantine consensus while preserving Bitcoin’s open
membership by dynamically forming hash power-proportionate consensus groups that
represent recently-successful block miners. ByzCoin employs communication trees
to optimize transaction commitment and verification under normal operation while
guaranteeing safety and liveness under Byzantine faults, up to a near-optimal
tolerance of f faulty group members among 3f + 2 total. ByzCoin mitigates double
spending and selfish mining attacks by producing collectively signed transaction
blocks within one minute of transaction submission. Tree-structured communication
further reduces this latency to less than 30 seconds. Due to these optimizations,
ByzCoin achieves a throughput higher than Paypal currently handles, with a confirmation
latency of 15-20 seconds.
article_processing_charge: No
author:
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Philipp
full_name: Jovanovic, Philipp
last_name: Jovanovic
- first_name: Nicolas
full_name: Gailly, Nicolas
last_name: Gailly
- first_name: Ismail
full_name: Khoffi, Ismail
last_name: Khoffi
- first_name: Linus
full_name: Gasser, Linus
last_name: Gasser
- first_name: Bryan
full_name: Ford, Bryan
last_name: Ford
citation:
ama: 'Kokoris Kogias E, Jovanovic P, Gailly N, Khoffi I, Gasser L, Ford B. Enhancing
bitcoin security and performance with strong consistency via collective signing.
In: Proceedings of the 25th USENIX Conference on Security Symposium. USENIX
Association; 2016:279–296.'
apa: 'Kokoris Kogias, E., Jovanovic, P., Gailly, N., Khoffi, I., Gasser, L., &
Ford, B. (2016). Enhancing bitcoin security and performance with strong consistency
via collective signing. In Proceedings of the 25th USENIX Conference on Security
Symposium (pp. 279–296). Austin, TX, United States: USENIX Association.'
chicago: Kokoris Kogias, Eleftherios, Philipp Jovanovic, Nicolas Gailly, Ismail
Khoffi, Linus Gasser, and Bryan Ford. “Enhancing Bitcoin Security and Performance
with Strong Consistency via Collective Signing.” In Proceedings of the 25th
USENIX Conference on Security Symposium, 279–296. USENIX Association, 2016.
ieee: E. Kokoris Kogias, P. Jovanovic, N. Gailly, I. Khoffi, L. Gasser, and B. Ford,
“Enhancing bitcoin security and performance with strong consistency via collective
signing,” in Proceedings of the 25th USENIX Conference on Security Symposium,
Austin, TX, United States, 2016, pp. 279–296.
ista: 'Kokoris Kogias E, Jovanovic P, Gailly N, Khoffi I, Gasser L, Ford B. 2016.
Enhancing bitcoin security and performance with strong consistency via collective
signing. Proceedings of the 25th USENIX Conference on Security Symposium. SEC:
Security Symposium, 279–296.'
mla: Kokoris Kogias, Eleftherios, et al. “Enhancing Bitcoin Security and Performance
with Strong Consistency via Collective Signing.” Proceedings of the 25th USENIX
Conference on Security Symposium, USENIX Association, 2016, pp. 279–296.
short: E. Kokoris Kogias, P. Jovanovic, N. Gailly, I. Khoffi, L. Gasser, B. Ford,
in:, Proceedings of the 25th USENIX Conference on Security Symposium, USENIX Association,
2016, pp. 279–296.
conference:
end_date: 2016-08-12
location: Austin, TX, United States
name: 'SEC: Security Symposium'
start_date: 2016-08-10
date_created: 2020-08-26T12:08:35Z
date_published: 2016-09-01T00:00:00Z
date_updated: 2021-01-12T08:18:00Z
day: '01'
extern: '1'
external_id:
arxiv:
- '1602.06997'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1602.06997
month: '09'
oa: 1
oa_version: Published Version
page: 279–296
publication: Proceedings of the 25th USENIX Conference on Security Symposium
publication_identifier:
isbn:
- '9781931971324'
publication_status: published
publisher: USENIX Association
quality_controlled: '1'
status: public
title: Enhancing bitcoin security and performance with strong consistency via collective
signing
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2016'
...
---
_id: '8300'
abstract:
- lang: eng
text: The integration of social networking concepts into Internet of Things systems
is a burgeoning topic of research that promises to support novel and more powerful
applications. In this paper we focus on the design and implementation of a highly
scalable Trust and Reputation Model for the Internet of Things based on the social
approach that the COSMOS project introduces, as part of its final results. We
create our model by combining popular solutions proposed for Peer-to-Peer and
mobile ad-hoc networks and adapting them on the Internet of Things concept. Each
Thing can compute the Trust index of another Thing based on its own experiences,
while it has the capability of determining its Reputation Index either by consulting
its other “friends” (Followees) or referring to the Platform, a management system
used in COSMOS. The model is tested through simulations of the proposed social
system, demonstrating the ability of TRM-SIoT to achieve the Social Exclusion
of malicious nodes and collectives from the network, with low computational overhead
and high scalability. Furthermore, due to the adaptive nature of the system, Social
Reintegration of these nodes is also possible.
article_number: '7733612'
article_processing_charge: No
author:
- first_name: Eleftherios
full_name: Kokoris Kogias, Eleftherios
id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
last_name: Kokoris Kogias
- first_name: Orfefs
full_name: Voutyras, Orfefs
last_name: Voutyras
- first_name: Theodora
full_name: Varvarigou, Theodora
last_name: Varvarigou
citation:
ama: 'Kokoris Kogias E, Voutyras O, Varvarigou T. TRM-SIoT: A scalable hybrid trust
& reputation model for the social Internet of Things. In: 2016 IEEE 21st
International Conference on Emerging Technologies and Factory Automation.
IEEE; 2016. doi:10.1109/etfa.2016.7733612'
apa: 'Kokoris Kogias, E., Voutyras, O., & Varvarigou, T. (2016). TRM-SIoT: A
scalable hybrid trust & reputation model for the social Internet of Things.
In 2016 IEEE 21st International Conference on Emerging Technologies and Factory
Automation. Berlin, Germany: IEEE. https://doi.org/10.1109/etfa.2016.7733612'
chicago: 'Kokoris Kogias, Eleftherios, Orfefs Voutyras, and Theodora Varvarigou.
“TRM-SIoT: A Scalable Hybrid Trust & Reputation Model for the Social Internet
of Things.” In 2016 IEEE 21st International Conference on Emerging Technologies
and Factory Automation. IEEE, 2016. https://doi.org/10.1109/etfa.2016.7733612.'
ieee: 'E. Kokoris Kogias, O. Voutyras, and T. Varvarigou, “TRM-SIoT: A scalable
hybrid trust & reputation model for the social Internet of Things,” in 2016
IEEE 21st International Conference on Emerging Technologies and Factory Automation,
Berlin, Germany, 2016.'
ista: 'Kokoris Kogias E, Voutyras O, Varvarigou T. 2016. TRM-SIoT: A scalable hybrid
trust & reputation model for the social Internet of Things. 2016 IEEE 21st
International Conference on Emerging Technologies and Factory Automation. ETFA:
Conference on Emerging Technologies and Factory Automation, 7733612.'
mla: 'Kokoris Kogias, Eleftherios, et al. “TRM-SIoT: A Scalable Hybrid Trust &
Reputation Model for the Social Internet of Things.” 2016 IEEE 21st International
Conference on Emerging Technologies and Factory Automation, 7733612, IEEE,
2016, doi:10.1109/etfa.2016.7733612.'
short: E. Kokoris Kogias, O. Voutyras, T. Varvarigou, in:, 2016 IEEE 21st International
Conference on Emerging Technologies and Factory Automation, IEEE, 2016.
conference:
end_date: 2016-09-09
location: Berlin, Germany
name: 'ETFA: Conference on Emerging Technologies and Factory Automation'
start_date: 2016-09-06
date_created: 2020-08-26T11:48:54Z
date_published: 2016-09-09T00:00:00Z
date_updated: 2021-01-12T08:17:59Z
day: '09'
doi: 10.1109/etfa.2016.7733612
extern: '1'
language:
- iso: eng
month: '09'
oa_version: None
publication: 2016 IEEE 21st International Conference on Emerging Technologies and
Factory Automation
publication_identifier:
isbn:
- '9781509013142'
publication_status: published
publisher: IEEE
quality_controlled: '1'
status: public
title: 'TRM-SIoT: A scalable hybrid trust & reputation model for the social Internet
of Things'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2016'
...