An Improved Lattice-Based Ring Signature With Unclaimable Anonymity in the Standard Model

Abstract Ring signatures enable a user to sign messages on behalf of an arbitrary set users, called the ring, without revealing exactly which member that ring actually generated signature. The signer-anonymity property makes have been active research topic. Recently, Park and Sealfon (PS; CRYPTO’19) presented important anonymity notion named signer-unclaimability constructed lattice-based signature scheme with unclaimable in standard model; however, it did not consider unforgeable w.r.t. adversarially chosen-key attack (the public key may contain keys created by adversary) size grows quadratically message. In this work, we propose new model. particular, our work improves security efficiency PS is attack, linearly size.