Ring signatures based on middle-product learning with errors problems

Abstract

© Springer Nature Switzerland AG 2019. Lattice-based (linkable) ring signatures are an important notion to cryptography since it protects signer anonymity against quantum computers. In this paper, we proposed a new lattice-based linkable ring signature scheme using a variant of Learning with Errors problem called Middle-Product Learning with Errors (MPLWE). The proposed scheme follows a framework from [10, 12] with the following improvements. Firstly, this scheme relies on a much weaker assumption. Secondly, our approach relies on a decisional problem, thus, the security analysis does not require the Forking Lemma which has been a fundamental obstacle for provable security under the quantum random oracle model (QROM).