A novel post-quantum threshold oblivious signature scheme is presented. Oblivious signatures enable a requester to obtain a signature on a single selected message from a set of candidates without revealing the selection to the signer. Unlike blind signatures, the signer may be aware of the candidate set. To mitigate single-point failures the scheme employs Shamir’s secret sharing to distribute signing authority among multiple participants. To address quantum threats, it leverages isogeny-based cryptography founded on the Group Action Inverse Problem for post-quantum resilience. The construction adapts an existing isogeny-based oblivious signature by introducing a trusted dealer. The signing protocol is multi-party; verification confirms signature validity on the selected message without revealing secret information. Security reduces to the hardness of Group Action Inverse Problem and the security of the secret-sharing scheme in the semi-honest model, covering corrupted dealers, users, and coalitions of fewer than the threshold number of signers. The threshold design eliminates dependence on a single signer, preventing unauthorized signatures after key compromise. Theoretical contributions advance threshold cryptography with post-quantum primitives; practical applications include anonymous voting, secure transactions, and privacy-preserving distributed systems. Future directions include malicious adversary models and integrations with other post-quantum primitives.

International Scientific-Technical Conference on Actual Problems of Electronic Instrument Engineering (APEIE)Nov 14, 20250 citations

An identity-verifiable quantum threshold group signature scheme based on three-particle GHZ states

Zhi-Ming Deng, Dianjun Lu, Teng Chen +1 more

Abstract With the advancement of the new generation of information technology in recent years, quantum digital signatures have been widely concerned. Among them, quantum threshold group signatures have become a hot research field due to their advantages such as low cost and strong scalability. Therefore, in this paper, we propose an identity-verifiable quantum threshold group signature scheme based on three-particle GHZ states. The characteristics of the scheme are as follows. The signers can reconstruct the key K for signature’s generation and verification by using the Shamir threshold secret sharing scheme. A quantum signature is generated by performing controlled-not operations, von Neumann measurements, and quantum Fourier transform. When the signature is verified, only classical hash values need to be compared, without comparing quantum states. Identity verification is performed between participants by using hash functions. The efficiency of the scheme is improved by using super-dense coding. Security analysis shows that our scheme is unforgeable and undeniable.

Laser PhysicsMar 28, 20249 citations