Research Of Computer Image Encryption Techniques Based On Chaotic Sequences Algorithm

With the development at full speed of Internet technology and multimedia technology, multimedia communication becomes the important means that people carry on information interchange gradually; people can exchange various kinds of information through the network and carry on online trade, etc. Because the information of images comparing other information have the characteristic of being direct and vivid, the images utilize far and wide by the mankind and become one of the main means that the mankind expresses information. To the information of the image, the traditional cryptography still lacks enough research. In recent years, the international academic meeting about the data encryption held in succession, the information of the image encryption becomes one of important topics.The encryption of the;image has extensive application backgrounds. The encryption of the image not only concerns personal communication secrets but also concerns the business secrets of an enterprise and existence of enterprises and even concerns the security of a country. For example, the patient's case data (including the patient's photo) must spread on the net after encrypting according to the stipulations of law in the hospital, this needs reliable encryption. As our country develops the electronic examination and approval system in a more effective manner, a large number of individuals and unit's information will travel in the electronic examination and approval system built. The question of information safety becomes the focus in E-government. Because all materials in the electronic examination and approval system turn into the information of the image, in this system, the security of the image is all to care. So, the security and keeping secret of the image seem more and more important, the encryption of the image becomes one of the focuses that the computer image studies at present.Chaotic sequences have several good properties, such as the ease of the generation, their sensitive dependence on its initial parameters, and specially white noise alike, at the same timeit can be reproduced precisely based on the initial condition. And their discrete mapping sequences have a same property. Because of these good properties, chaotic system can be used to image encryption. In the paper, an image encryption algorithm is proposed based on chaotic sequences and image scrambling. First, as the initial parameter is the key, the chaotic sequences can be generated based on key. Then according to discrete sequences, the RGB value of pixel is modified randomly. At the same time, two directions XOR scrambling algorithm based on DES is used to scramble the image on space. Software simulation results prove the algorithm possesses the feature of low computational complexity, dependence on its initial parameters and high security.