分野別セミナー

A blind ring signature scheme is a combination of a ring signature one and a blind signature one. It allows not only members of a group to sign messages on behalf of the group without revealing their identities but also the client who possesses the message to blind it before sending to the group to be signed. Blind ring signature schemes are essential components in e-commercial, voting etc. At ASIACRYPT 2010, R{\"u}ckert prosed a first lattice-based blind signature scheme from Lyubashevsky's ID scheme using Fiat-Shamir transformation. Also,at AfricaCrypt 2013, Aguilar-Melchor et al. introduced the first ring signature scheme based on lattices, which was adapted from the signature scheme by Lyubashevsky whose security reduces to the hardness of short integer solutions (\textsf{SIS}) problem. In this paper, we propose the first blind ring signature scheme based on lattices. More precisely, our proposed scheme is proven to be secure in random oracle model under the hardness of \textsf{SIS} problem.