Research On Chaotic Image Encryption Algorithm

Information security is an eternal topic. When people spread important information through an insecure network, how to prevent the leakage of information has been becoming a critical issue. In fact, chaos property of chaotic system is similar to confusion, diffusion and pseudo-random property of cryptography. Research on the safety and efficient encryption algorithms based on chaotic system become an important research area. Chaotic has unique cryptographic feature that makes it’s suit for encryption.The security of chaotic systems based on encryption algorithm largely depends on the performance of the chaotic system, how to design a better chaos system to encrypt also become a hot topic. It’s extremely difficult to design new chaotic system, although the high-dimensional system’s structure is more complex,and it owns high Lyapunov exponent for the chaotic sequence encryption, which can achieve higher security, but it’s difficult to implement and it’s computation is large. The structure of one-dimensional systems is simple,it’s also easy to implement.The existing one-dimensional and high-dimensional chaos system have the following problem,such as discrete intervals,small parameter range and uneven distribution of chaotic sequence. How can we use effective method to improve the existing chaotic system to make it to be more suitable for digital image encryption applications. Aiming at the above issues, a new one-dimensional chaotic system is approsed through combining the existing one-dimensional chaotic systems appropriately, its Lyapunov exponent is high, chaos range is wide, chaos section is continuous, chaotic sequence distribute uniformity and it has more control parameters. This paper studied the performance of the new chaos system by comparing bifurcation diagram and Lyapunov exponent diagram. It proposed a new decryption algorithms based on this new chaotic system.Finally, it verified the effection of encryption algorithms and anti-attack capability through Matlab software. The results show that the new image encryption algorithm based on one-dimension chaotic system has better security, and its easy to implement. Meanwhile it proposed a encryption and decryption algorithms used for string and file, it is verified by VC6.0 using C language. Finally, the image encryption algorithm is proved by developmentplatform made by programmable logic device.