The Research Of Images Encryption Based On Chaotic Technology

To encrypt images is one of the important methods to ensure information safety. Recently, encryption technology has been developed quickly and many image encrypt methods have been put forwarded. Chaos-based image encryption technique is a new encryption technique for images. It utilizes chaos random sequence to encrypt image, which is an efficient way to deal the intractable problem of fast and highly secure image encryption. However, the Chaos-based image encryption technique has some deficiencies, such as the limited accuracy problem.First, this thesis summarizes the current image's encryption algorithm, analyzes these algorithm's merit and the cause of inconformity for images of encryption. Then, we study chaos theory and the algorithm, take a part of algorithm for simulation, find out the shortage of images encryption algorithm. According to the above study, Chaos-based image array disturbed algorithm has been improved and a new image encryption system has been developed based on the improved algorithm.The new encryption system realizes images encryption by disturbing color value of each image point and the array of original image, uses double Logistic map produce the array of original chaotic sequence. The sequences are conferred into binary form, and then use it to disturb color value of original image. Image array disturbed algorithm has been improved to implement multiple permute better. The algorithm shortens its encryption time, so it fits image encryption well. After theoretic analysis and simulation experiments, the system has higher sensitivity to initial conditions, better security and encryption effects, so it is adapt for images encryption.