Research On Data Encryption Algorithm Based On Chaos Theory

With the development of Internet technology, communication between people becomes faster and more convenient, but the security of data storage and transmission through the Internet has received more attention. Since more and more encryption algorithms have been cracked, designing a safe and effective algorithm becomes a problem that needs to be solved urgently.Chaotic maps have initial conditions sensitivity, long-term unpredictability, pseudo-randomness, ergodicity and other characteristics. These characteristics are essentially interrelated to "Confusion" and "Diffusion" of cryptography. So the chaos theory as a new branch of cryptography, has been widely researched and applied. Image is featured with huge amount of data, high redundancy and strong correlation between pixels than text. It requires a higher level of the encryption algorithm. This paper is starting from this problem. The image encryption technology based on chaos theory is studied.According to the chaos theory and encryption technology, the application of chaos theory in encryption is discussed in this paper. For chaos is affected by limited word length when implemented by a computer, there is a degradation problem with dynamic properties. So an improvement measure is presented. Based on the analysis of the characteristics of Logistic map and Cubic map, a compound chaotic system with variable parameters is designed. The characteristics of chaotic sequence are improved through the compound system.An image data encryption algorithm is also constructed in this paper based on the chaotic sequence that is generated from the improved algorithm, Combine the two methods of pixel position scrambling and pixel value spreading. Ciphertext feedback is also introduced in diffusion section. The change of each pixel point spreads to all the other pixels through the encryption processing in an ascending order and a descending order. The simulation experiment indicates that the algorithm can achieve a good encryption effect. It has a certain feasibility and safety.