---
res:
  bibo_abstract:
  - 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.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Alexei
      foaf_name: Zamyatin, Alexei
      foaf_surname: Zamyatin
  - foaf_Person:
      foaf_givenName: Mustafa
      foaf_name: Al-Bassam, Mustafa
      foaf_surname: Al-Bassam
  - foaf_Person:
      foaf_givenName: Dionysis
      foaf_name: Zindros, Dionysis
      foaf_surname: Zindros
  - foaf_Person:
      foaf_givenName: Eleftherios
      foaf_name: Kokoris Kogias, Eleftherios
      foaf_surname: Kokoris Kogias
      foaf_workInfoHomepage: http://www.librecat.org/personId=f5983044-d7ef-11ea-ac6d-fd1430a26d30
    orcid: 0000-0002-8827-3382
  - foaf_Person:
      foaf_givenName: Pedro
      foaf_name: Moreno-Sanchez, Pedro
      foaf_surname: Moreno-Sanchez
  - foaf_Person:
      foaf_givenName: Aggelos
      foaf_name: Kiayias, Aggelos
      foaf_surname: Kiayias
  - foaf_Person:
      foaf_givenName: William J.
      foaf_name: Knottenbelt, William J.
      foaf_surname: Knottenbelt
  bibo_doi: 10.1007/978-3-662-64331-0_1
  bibo_volume: '12675 '
  dct_date: 2021^xs_gYear
  dct_identifier:
  - UT:000712016200001
  dct_isPartOf:
  - http://id.crossref.org/issn/0302-9743
  - http://id.crossref.org/issn/1611-3349
  - http://id.crossref.org/issn/9-783-6626-4330-3
  dct_language: eng
  dct_publisher: Springer Nature@
  dct_title: 'SoK: Communication across distributed ledgers@'
...