The Research On Chaotic Sequences On Image Information Encryption And Constructive Method Of Frequency Hopping Sequence

The chaotic phenomenon is deterministic and random-like in non-linear dynamic system.The chaotic sequences created by the chaotic system are the complexity ,randomness and sensitivity to initial conditions. As a result,the chaotic system have performed comprehensive application in the field of secure communication. The thesis sets out to study on producing of chaotic sequence and its application to the image encryption and Frequency Hopping communication system.The fundamental conceptions and the related knowledge of the chaos are introduced in the paper systematically.The ways and the requirements of the image encryption are suggested.And the important researches are done on the algorithms of the image encryption. This paper presents a new chaotic color image encryption algorithm which shuffling the positions and changing the values of image pixels are combined. Firstly, the general Arnold map is used to shuffle the positions of the image pixels in the spatial-domain. Then the sequence values of the Chen chaotic system is adopted to generate integer keys for the image encryption, and the shuffled image is encrypted by the integer keys pixel by pixel. The experimental results demonstrate that the image encryption algorithm shows advantages of large key space,high-level security, and the ciphered image has random-like distribution behavior of image values, adjacent pixels have zero co-correlation properties.This paper summarizes advantages of FH communication,the status quo of FH communication system design and frequencies design.Then the function of the FH sequences, properties,design demands and theories of FH frequences with given minimum gap are summarized and analyzed.Finally,an improved chaos map (varying-parameter Tent chaos map) is put forward . And a kind of new chaotic frequency hopping sequence is presented. An improved given gap method is also suggested.Theoretic analysis and simulation show that the proposed FH sequences feature good uniform frequency distribution property,hamming correlation property and wide frequency gap as existing good FH sequences. Furthermore,they possess of initial value sensitivity and huge amount of numbers.