Research On And Implementation Of Quantum Cryptography Communications Based On BB84 Protocol

In the fields of military communications systems and E-Commerce and many others, information security and confidentiality is very important. Quantum key distribution systems produce and distribute keys based on the basic principle of quantum mechanics. It ensures that the absolute secrecy of the key in the process of distribution and the security of the information exchanged in the systems. This paper researches on the implementation of the quantum cryptography communications based on BB84 protocol.Firstly, in this dissertation, we propose a quantum communication system model, discuss its security, and analyze in detail the security of the BB84 protocol under the channels with noise or not.Secondly, we design a quantum cryptography communications system under the optical fiber channels based on polarization coding, and implement the software of BB84 protocol based on Winsock network programming.Thirdly, based on the research of AES algorithm, we program to implement the algorithm which supports three kinds of keys with different lengths (128bits, 192bits, 256bits). According to some tests with different lengths of the keys, the results show that the encryption and decryption module of the designed AES algorithm is completely correct.Finally, we encrypt and decrypt some documents and pictures as examples using the keys obtained from the BB84 protocol.