Lattice-Based Ring Signature Scheme under the Random Oracle Model

TL;DR

This paper introduces a new lattice-based ring signature scheme that is more efficient and produces shorter signatures, with security based on the SIS problem and proven strong unforgeability in the random oracle model.

Contribution

It presents a novel lattice-based ring signature scheme extending previous trapdoor-free signatures, with security reduction to the SIS problem and improved efficiency.

Findings

Scheme is strongly unforgeable against adaptive chosen message attacks.

Security is reducible to the hardness of the SIS problem.

The scheme offers shorter signatures and better efficiency than existing lattice-based schemes.

Abstract

On the basis of the signatures scheme without trapdoors from lattice, which is proposed by Vadim Lyubashevsky in 2012, we present a new ring signature scheme from lattice. The proposed ring signature scheme is an extension of the signatures scheme without trapdoors. We proved that our scheme is strongly unforgeable against adaptive chosen message in the random oracle model, and proved that the security of our scheme can be reduced to the hardness of the small integer solution (SIS) problem by rejection samplings. Compared with the existing lattice-based ring signature schemes, our new scheme is more efficient and with shorter signature length.