Traceable conditional privacy-preserving multi-designated verifier signature scheme

Although digital signature technology ensures data integrity and signer non-repudiation, its public verification feature may lead to the disclosure of sensitive information. Existing designated verifier signature (DVS) schemes face a trade-off between privacy protection and dispute arbitration, and they require pre-binding of the designated verifier's identity during signature generation. Additionally, some designated verifier digital signature schemes rely on centralized traceability authorities for traceability, posing risks of key leakage and trust distribution. To address these issues, this paper proposes a Traceable Conditional Privacy-Preserving Multi-Designated Verifier Signature (TCP-MDVS) scheme. The scheme integrates the advantages of DVS and Universal Designated Verifier Signature (UDVS) by constructing a group of coprime moduli and embedding signature components, enabling a single signature to support independent verification by multiple verifiers without requiring pre-registration of verifier keys. The scheme supports dynamic authorization, eliminating the need for signature reconstruction or the introduction of third-party intermediaries. In terms of dispute arbitration, by selectively disclosing specific prime parameters, a publicly verifiable evidence chain can be generated, which not only overcomes the non-transferability limitation of UDVSP but also avoids the dependence on centralized traceability authorities inherent in Traceable Universal Designated Verifier Signature Proof (TUDVSP). Furthermore, the TCP-MDVS scheme hides the signature's structure, thus resisting cross-component correlation attacks, providing an efficient, secure, and privacy-controllable signature framework for dynamic multi-verifier scenarios.