UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Winkle: Foiling Long-Range Attacks in Proof-of-Stake Systems

Azouvi, S; Danezis, G; Nikolaenko, V; (2020) Winkle: Foiling Long-Range Attacks in Proof-of-Stake Systems. In: AFT 2020 - Proceedings of the 2nd ACM Conference on Advances in Financial Technologies. (pp. pp. 189-201). ACM: Association for Computing Machinery: New York, NY, USA. Green open access

[thumbnail of 2019-1440.pdf]
Preview
Text
2019-1440.pdf - Accepted Version

Download (1MB) | Preview

Abstract

Winkle protects any validator-based byzantine fault tolerant consensus mechanisms, such as those used in modern Proof-of-Stake blockchains, against long-range attacks where old validators' signature keys get compromised. Winkle is a decentralized secondary layer of client-based validation, where a client includes a single additional field into a transaction that they sign: a hash of the previously sequenced block. The block that gets a threshold of signatures (confirmations) weighted by clients' coins is called a "confirmed"checkpoint. We show that under plausible and flexible security assumptions about clients the confirmed checkpoints can not be equivocated. We discuss how client key rotation increases security, how to accommodate for coins' minting and how delegation allows for faster checkpoints. We evaluate checkpoint latency experimentally using Bitcoin and Ethereum transaction graphs, with and without delegation of stake.

Type: Proceedings paper
Title: Winkle: Foiling Long-Range Attacks in Proof-of-Stake Systems
Event: AFT 2020 - 2nd ACM Conference on Advances in Financial Technologies
ISBN-13: 9781450381390
Open access status: An open access version is available from UCL Discovery
DOI: 10.1145/3419614.3423260
Publisher version: https://doi.org/10.1145/3419614.3423260
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Computer Science
URI: https://discovery.ucl.ac.uk/id/eprint/10172332
Downloads since deposit
5Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item