Cryptology ePrint Archive: Report 2017/1044

Strain: A Secure Auction for Blockchains

Erik-Oliver Blass and Florian Kerschbaum

Abstract: We present Strain, a new auction protocol running on top of blockchains and guaranteeing bid confidentiality against fully-malicious parties. As our goal is efficiency and low blockchain latency, we abstain from using traditional, highly interactive MPC primitives such as secret shares. We focus on a slightly weaker adversary model than MPC which allows Strain to achieve constant latency in both the number of parties and the bid length. The main idea behind Strain is a new maliciously-secure two-party comparison mechanism executed between any pair of bids in parallel. Using zero-knowledge proofs, Strain broadcasts the outcome of comparisons on the blockchain in a way that all parties can verify each outcome. Strain's latency is not only asymptotically optimal, but also efficient in practice, requiring a total of just 4 blocks of the underlying blockchain. Strain provides typical auction security requirements such as non-retractable bids against fully-malicious adversaries.

Category / Keywords: applications /

Date: received 24 Oct 2017, last revised 18 Jun 2018

Contact author: erik-oliver blass at airbus com

Available format(s): PDF | BibTeX Citation

Version: 20180618:150354 (All versions of this report)

Short URL: ia.cr/2017/1044