A novel quantum multiparty blind signature scheme based on χ state

Quantum digital signature, as an extension of classical digital signature, has become an important research content in quantum cryptography. Quantum blind signature combines the advantages of classical blind signature and quantum signature, which can ensure the unconditional security of the scheme based on the realization of the blinded signature of the message, and can be effectively applied in many real-world scenarios. This paper uses the four-particle $\chi$ state as a communication channel, combined with quantum teleportation technology to propose a new quantum multi-party blind signature protocol, which has the following characteristics: First, the Toeplitz hash function based on the linear shift register is introduced to blind the message, and the length of the blinded message can be adjusted according to the actual demand to increase the flexibility of the scheme; Second, through multi-party participation, the blind signature of multi-bit messages can be realized, and the signature efficiency can be improved. Compared with other quantum blind signatures, the signature efficiency has been greatly improved; Finally, using the four-particle $\chi$ state as a quantum channel can make the scheme use fewer resources to transmit data and increases the security of the scheme. Through security analysis, it can be seen that the scheme has blindness, nonrepudiation and unforgeability.