Quantum (t, m, n) Threshold Group Blind Signature Scheme with Flexible Number of Participants

With the progress of science and technology, as well as the development of quantum computing and quantum information theory, quantum digital signature schemes have become the focus of current research. Threshold quantum signature has been widely concerned because of its low cost, high security, strong scalability and other advantages. In this paper, we propose a quantum (t, m, n) threshold group blind signature scheme with flexible number of participants based on quantum entanglement swapping. This scheme has the following characteristics. Any m (t⩽ m⩽ n) signers can reconstruct the key K for signature verification by using the Shamir threshold secret sharing scheme and they can generate a signature, which reflects good flexibility in the number of signers. The blind operation of the scheme is XOR operations, which is easier to implement in real scenarios. Security analysis shows that our scheme has unforgeability and non-deniablity.