Trustworthy Systems

Cross-chain payment protocols with success guarantees


Rob van Glabbeek, Vincent Gramoli and Pierre Tholoniat


University of Sydney

UNSW Sydney


In this paper, we consider the problem of cross-chain payment whereby customers of different escrows—implemented by a bank or a blockchain smart contract—successfully transfer digital assets without trusting each other. Prior to this work, cross-chain payment problems did not require this success or any form of progress. We introduce a new specification formalism called Asynchronous Networks of Timed Automata (ANTA) to formalise such protocols. We present the first cross-chain payment protocol that ensures termination in a bounded amount of time and works correctly in the presence of clock skew. We then demonstrate that it is impossible to solve this problem without assuming synchrony, in the sense that each message is guaranteed to arrive within a known amount of time. We also offer a protocol that solves an eventually terminating variant of this cross-chain payment problem without synchrony, and even in the presence of Byzantine failures.

BibTeX Entry

    author           = {van Glabbeek, Robert and Gramoli, Vincent and Tholoniat, Pierre},
    date             = {2019-12-10},
    institution      = {Data61, CSIRO},
    keywords         = {Cross-chain payment protocols; distributed systems; fault tolerance; blockchain; asynchronous
                        networks of timed automata; asynchronous communication; clock skew; safety and liveness properties;
                        cross-chain deals.},
    month            = dec,
    numpages         = {22},
    paperurl         = {},
    publisher        = {CSIRO},
    title            = {Cross-Chain Payment Protocols with Success Guarantees},
    year             = {2019}