Research On Secure Quantum Identification And Information Signature Protocols

Communication security is a key problem in modern information society. Physically, the traditional cryptographic systems have intrinsic drawback since they have no capability to check the simple eavesdropping. In mathematical viewpoint, most of the traditional cryptographic systems are found on computional complexity problem, these arithmetics would be broken with the improvement of calculational capability. Fortunately, it is proven that this drawback can be offset by quantum cryptography for its two basical characteries: unconditi onal security and eavesdropping detectability. Focusing on the frontier research subjects of quantum cryptography,in the dissertation, we proposed a series of quantum authentication protocols and analyzed their security and efficiency in detail.These protocols involve quantum identification protocols, quantum signature protocols and a quantum secure direct communication protocol, the main results we obtained are as follows:In the field of quantum identification, (1) an identification protocol used in local quantum communication network was present. This protocol resolved the problem of identification in local quantum communication network, combining quantum key distribution technology, it would guarantee the messages secure absolutely in a local network. (2) An identification protocol used to identify the legal users in the cross-center networks was present.In the study of single-user quantum signature protocols, (1) a digital signature protocol based on qantum entanglement swapping was present, for qantum entanglement swapping is easy to realize, the present protocol can sign the classical digital message by the help of an administrator. (2) Two quantum digital signature schemes using the entanglement character of EPR pairs were present, one is based on comparing the measurement result and another one is based on teleportation. Both of them need not arbitrator and secret keys. (3) An authentic digital signature scheme useed to sign classical digital message was presented, it does not need an arbitrator to authenticate the signature unless some disputes had happened between the issuer and verifier. (4)A no arbitrator signature protocol used to sign quantum superposition states messges was present。Single-user quantum signature protocols can be used in the situation such as the bank pay for another according to his client's signature. In the study of multi-user quantum signature protocols, (1) a digital multi-signature protocol based on the controlled quantum teleportation was present, it supports two users to sign the classical digital messages at one time. (2)A quantum message multi-signature protocol based on the controlled quantum teleportation was present; it supports two users to sign the general superposition quantum states at one time. These above two quantum multi-signature protocols may be applied in the situations where an important file should be signed by two users. (3) We researched quantum sequential multi-signature problem and present a protocol based on quantum entanglement swapping for the first time. This protocol can sign the classical digital message as well as supports no-limited amounts of signatories, which can be applied in the situations where a file should be signed by the hierarchized users. (4) We researched quantum broadcasting multi-signature problem for the first time, and two quantum broadcasting multi-signature schemes are presented, one is used to sign classical digital messages and the other to sign quantum messages. This two protocols support no-limited amounts of signatories and can be applied in the situations where a file should be siged by all users in a group.In the field of quantum secure direct communication, a quantum telephone protocol including the dialing process and the talking one was proposed for the first time. In the dialing process, with their respective secret keys, the legitimate communicators Alice and Bob can pass the authentication by Charlie acting as a telephone company. In the talking process, Charlie provides the authenticated Alice and Bob with a quantum channel sequence, on which Alice and Bob can communicate with each other directly and privately by virtue of some encoding operations. Different from the insecure classical telephone having been used in our lives, the proposed quantum telephone protocol has asymptotically security and the communicators cannot disavow having used the quantum channels.