In this thesis, we study the secret communication based on the digital chaotic systems. Firstly, in paper introduce the character of the chaotic system and analyze the feasibility to the degenerateness in the field of the secure communication based on the chaotic technology. According to the principle of the digital and chaotic encryption techniques, a chaotic theory based encryption algorithm whose parameter change at random is designed. By utilizing the quantized value of array control chaos iteration, changing the parameter during the chaotic mapping iterative process at random, the random switch between chaotic multi-systems is realized, the purpose of disturbing the chaos track is achieved and chaos degenerateness is resisted. Using the one-dimension linear map chaotic system as pseudo-random sequence generator, a sequence encryption algorithm has been designed upon a pair of chaotic systems. The chaotic combination has outstanding characteristics of cryptography proved by the encryption theory and the image encryption test, it can meet the higher require of the encryption. |