Cryptology ePrint Archive: Report 2017/457
Universal Construction of Cheater-Identifiable Secret Sharing Against Rushing Cheaters without Honest Majority
Masahito Hayashi and Takeshi Koshiba
Abstract: For conventional secret sharing, if cheaters can submit possibly forged shares after observing shares of the honest users in the reconstruction phase, they can disturb the protocol and reconstruct the true secret. To overcome the problem, secret sharing scheme with properties of cheater-identification have been proposed. Existing protocols for cheater-identifiable secret sharing assumed non-rushing cheaters or honest majority. In this paper, we remove both conditions simultaneously, and give its universal construction from any secret sharing scheme. To resolve this end, we propose the concepts of "individual identification" and "agreed identification".
Category / Keywords: foundations / secret sharing, universal construction, rushing cheater, cheater- identification, without honest majority
Date: received 23 May 2017
Contact author: tkoshiba at waseda jp
Available format(s): PDF | BibTeX Citation
Version: 20170525:124835 (All versions of this report)
Short URL: ia.cr/2017/457
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