Theoretical Study On The Quantum Signature

Because digital signatures as an important branch of cryptography is the foundation to achieve network authentication, data integrity and non-repudiation services, as well as an important tool for e-commerce and signing electronic contract, so the digital signature in the modern secret system plays a very important role. Similar to public-key cryptography, lots of classic digital signature schemes based on public key cryptography can be broken by Shor’s algorithm. Therefore, many scholars pay attention to the quantum correspond of digital signature—quantum signature. Whatever it is classical digital signature or quantum signature, they all need to meet two safety requirements—non-forgery and non-repudiation. In addition, as an implementation of electronic signature, it is necessary to design more digital signatures for people’s convenience in real life.Firstly, we found that there are more than one security risk in the AQS(arbitration signature scheme) with Bell-states as the quantum channel which is based on quantum one-time pad and quantum teleportation, and the AQS without entangled states which uses a public board to overcome the verifier’s repudiation. One is that the verifier can forge signatures in his will through implementing any unitary operation to the message-signature pair, and the other one is that the signer can arbitrarily deny his signature by entanglement attacks to achieve his unlawful purpose. Secondly, we study the use of quantum information splitting as an basic idea and W-state as quantum channel to achieve a quantum signature verification by more than one verifier, this scheme is also combined with quantum key distribution, one-time pad, one-way function and decoy states to ensure security. Finally, we made a more general promotion to this program.