Cryptology ePrint Archive: Report 2019/262
Revisiting Post-Quantum Fiat-Shamir
Qipeng Liu and Mark Zhandry
Abstract: The Fiat-Shamir transformation is a useful approach to building non-interactive arguments (of knowledge) in the random oracle model. Unfortunately, existing proof techniques are incapable of proving the security of Fiat-Shamir in the quantum setting. The problem stems from (1) the difficulty of quantum rewinding, and (2) the inability of current techniques to adaptively program random oracles in the quantum setting.
In this work, we show how to overcome the limitations above in many settings. In particular, we give mild conditions under which Fiat-Shamir is secure in the quantum setting. As an application, we show that existing lattice signatures based on Fiat-Shamir are secure without any modifications.
Category / Keywords: foundations / quantum, Fiat-Shamir, signature, SIS
Date: received 1 Mar 2019
Contact author: qipengl at cs princeton edu
Available format(s): PDF | BibTeX Citation
Version: 20190306:025554 (All versions of this report)
Short URL: ia.cr/2019/262
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