Ring Signature and Identity-Based Ring Signature from Lattice Basis Delegation

In this paper, we propose a set of ring signature (RS) schemes and identity-based ring signature (IBRS) schemes using the lattice basis delegation technique due to [10,22]. The schemes are unforgeable and hold anonymity in the random oracle model. Using the method in [28,29], we also extend our constructions to obtain RS and IBRS schemes in the standard model. Our proposed ring signature schemes fit with ring trapdoor functions introduced by Brakerski and Kalai [31]. However, their work does not include ring signature in the random oracle model and identity-based ring signature schemes. For the lattice-based ring signature in the standard model, our construction is motivated by Boyen’s work [28] and results in shorter signatures than Brakeski-Kalai scheme. 1