We present a smart contract for generating unbiased randomness on a blockchain/ledger-style system. Our smart contract can be stored on a blockchain and be executed publicly whenever needed. In particular, our protocol is suitable for leader-election-style applications and for mitigating front-running attacks. We prove correctness and security of our smart contract within a formal model of a distributed ledger extended by financial incentives and smart contracts. To the best of our knowledge, our formalization is the first to capture the concept of “time” in the context of smart contracts. Furthermore, we show that our protocol is incentive compatible, namely, under some reasonable financial assumption, following the honest execution, even for an all but one corruptions, gives the most financial benefit. Technically, our smart contract utilizes recently-introduced non-malleable time-lock puzzles. At a very high level, these are cryptographic commitments that can be “force opened” after a predefined delay. Using those, we implement a commit-and-reveal-style protocol but where we consider the particulars of the blockchain setting.
|Original language||American English|
|Title of host publication||Cyber Security, Cryptology, and Machine Learning - 7th International Symposium, CSCML 2023, Proceedings|
|Editors||Shlomi Dolev, Ehud Gudes, Pascal Paillier|
|Publisher||Springer Science and Business Media Deutschland GmbH|
|Number of pages||16|
|State||Published - 2023|
|Event||7th International Symposium on Cyber Security, Cryptology, and Machine Learning, CSCML 2023 - Be'er Sheva, Israel|
Duration: 29 Jun 2023 → 30 Jun 2023
|Name||Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)|
|Conference||7th International Symposium on Cyber Security, Cryptology, and Machine Learning, CSCML 2023|
|Period||29/06/23 → 30/06/23|
Bibliographical notePublisher Copyright:
© 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.