Identity-based quantum signature based on Bell states

Based on the Bell states, an identity-based quantum signature scheme is proposed. In our scheme, the signer's private key is generated by a trusted third party called private key generator(PKG), while the signer's public key is his/her identity(such as his/her name or email address). The message to be signed is encoded into a Bell state sequence. To generate a quantum signature, the signer signs the Bell state sequence with his/her private key. The quantum signature can be verified by anyone with the signer's identity. Our quantum signature scheme has the advantages of the classical identity-based signature scheme. It need not use long-term quantum memory. On the other hand, in our scheme, during the signature verification phase, the verifier need not perform any quantum swap test. What is more, in our scheme, PKG can arbitrate the disputation of losing quantum signature, which cannot be arbitrated in most of the quantum signature schemes. Our scheme also has the security properties of non-repudation, unforgeability, etc. Our signature is more secure, efficient and practicable than the similar schemes.