Paper 2019/1303

A simpler construction of traceable and linkable ring signature scheme

Wulu Li and Lei Chen and Xin Lai and Xiao Zhang and Jiajun Xin

Abstract

Traceable and linkable ring signature scheme (TLRS) plays a major role in construction of regulatable privacy-preserving blockchains, as it empowers the regulator with traceability of signers' identities. A recent work by Li et al. gives a modular construction of TLRS by usage of classic ring signature, one-time signature and zero-knowledge proofs, and has security against malicious regulators. In this paper, we introduce sTLRS, a simpler modification of TLRS constructed directly from classic ring signature, without additional one-time signature and zero-knowledge proofs for validity of users' public keys, with public key size reduced by 80% and verification time reduced by over 50%. Moreover, we can further modify the sTLRS to achieve anonymity, unforgeability, linkability, nonslanderability and traceability against malicious regulators.