Multi-party ring quantum digital signatures

Abstract

Quantum digital signatures (QDSs), which are unforgeable, non-repudiable, and transferable, are widely used in quantum communication networks. Unfortunately, previous protocols have often relied on three-party models for security analysis and experimental verification. As the number of parties increases, the number of quantum links required increases exponentially, undoubtedly leading to high channel losses and cost for multi-party QDSs. This study proposes a multi-party ring QDS scheme that can effectively deal with the issue of redundant quantum links. Furthermore, compared with the previously proposed QDS protocols, our protocol can prevent repudiation attacks without symmetry operation or swap test. Hence, it also can reduce the possibility of forging attacks by eliminating the possibility of forgery using illegal strings.