Paper 2017/573
Ouroboros Praos: An adaptively-secure, semi-synchronous proof-of-stake protocol
Abstract
We present ``Ouroboros Praos'', a proof-of-stake blockchain protocol that, for the first time, provides security against fully-adaptive corruption in the semi-synchronous setting: Specifically, the adversary can corrupt any participant of a dynamically evolving population of stakeholders at any moment so long as the stakeholder distribution maintains an honest majority of stake; furthermore, the protocol tolerates an adversarially-controlled message delivery delay unknown to protocol participants. To achieve these guarantees we formalize and realize in the universal composition setting a suitable form of forward secure digital signatures and a new type of verifiable random function that maintains unpredictability under malicious key generation. Our security proof develops a general combinatorial framework for the analysis of semi-synchronous blockchains that may be of independent interest. We prove our protocol secure under standard cryptographic assumptions in the random oracle model.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- A minor revision of an IACR publication in EUROCRYPT 2018
- Keywords
- blockchainconsensusproof of stake.
- Contact author(s)
- peter gazi @ iohk io
- History
- 2023-04-27: last of 3 revisions
- 2017-06-14: received
- See all versions
- Short URL
- https://ia.cr/2017/573
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2017/573,
author = {Bernardo David and Peter Gaži and Aggelos Kiayias and Alexander Russell},
title = {Ouroboros Praos: An adaptively-secure, semi-synchronous proof-of-stake protocol},
howpublished = {Cryptology {ePrint} Archive, Paper 2017/573},
year = {2017},
url = {https://eprint.iacr.org/2017/573}
}
