## Cryptology ePrint Archive: Report 2016/889

Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol

Aggelos Kiayias and Alexander Russell and Bernardo David and Roman Oliynykov

Abstract: We present Ouroboros,'' the first blockchain protocol based on proof of stake with rigorous security guarantees. We establish security properties for the protocol comparable to those achieved by the bitcoin blockchain protocol. As the protocol provides a proof of stake'' blockchain discipline, it offers qualitative efficiency advantages over blockchains based on proof of physical resources (e.g., proof of work). We also present a novel reward mechanism for incentivizing proof of stake protocols and we prove that, given this mechanism, honest behavior is an approximate Nash equilibrium, thus neutralizing attacks such as selfish mining. We also present initial evidence of the practicality of our protocol in real world settings by providing experimental results on transaction confirmation and processing.

Category / Keywords: blockchain, consensus, proof of stake.

Original Publication (with major differences): IACR-CRYPTO-2017

Date: received 12 Sep 2016, last revised 20 Jul 2019

Contact author: akiayias at inf ed ac uk

Available format(s): PDF | BibTeX Citation

Note: various minor corrections in the previous major revision.

Short URL: ia.cr/2016/889

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