Divide & Scale: Formalization and roadmap to robust sharding
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.
Download
No fulltext has been uploaded. References only!
Conference Paper
| Published
| English
Scopus indexed
Author
Avarikioti, Zeta;
Desjardins, AntoineISTA;
Kokoris Kogias, LefterisISTA;
Wattenhofer, Roger
Department
Series Title
LNCS
Abstract
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.
Using 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.
Publishing Year
Date Published
2023-06-01
Proceedings Title
30th International Colloquium on Structural Information and Communication Complexity
Acknowledgement
The work was partially supported by the Austrian Science Fund (FWF) through the project CoRaF (grant agreement 2020388).
Volume
13892
Page
199-245
Conference
SIROCCO: Structural Information and Communication Complexity
Conference Location
Alcalá de Henares, Spain
Conference Date
2023-06-06 – 2023-06-09
ISBN
ISSN
eISSN
IST-REx-ID
Cite this
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
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
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.
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.
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.
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.