Cryptology ePrint Archive: Report 2020/260

Lattice-based (Partially) Blind Signature without Restart

Samuel Bouaziz-Ermann and Sébastien Canard and Gautier Eberhart and Guillaume Kaim and Adeline Roux-Langlois and Jacques Traoré

Abstract: We present in this paper a blind signature and its partially blind variant based on lattices assumptions. Blind signature is a cornerstone in privacy-oriented cryptography and we propose the first lattice based scheme without restart. Compare to related work, the key idea of our construction is to provide a trapdoor to the signer in order to let him perform some gaussian pre-sampling during the signature generation process, preventing this way to restart from scratch the whole protocol. We prove the security of our scheme under the ring k-SIS assumption, in the random oracle model. We also explain security issues in the other existing lattice-based blind signature schemes. Finally, we propose a partially blind variant of our scheme, which is done with no supplementary cost, as the number of elements generated and exchanged during the signing protocol is exactly the same.

Category / Keywords: public-key cryptography / blind signature, partially blind, lattices, rejection sampling, k-SIS problem

Date: received 25 Feb 2020

Contact author: guillaume kaim at orange com

Available format(s): PDF | BibTeX Citation

Version: 20200225:204836 (All versions of this report)

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