An Image Encryption Scheme Based on Chaotic Systems

An image encryption scheme based on chaotic systems is proposed in this paper. By combining the spatial-domain encryption of digital images and the traditional stream ciphers technology, the security of the encryption scheme is enhanced effectively. Instead of encrypting an image in a chaotic signal directly, the proposed scheme uses two chaotic systems based on the thought of higher secrecy of multi-system. One of the chaotic systems is used to generate a chaotic sequence. Then this chaotic sequence is transformed into a binary stream by a threshold function. The other chaotic system is used to construct a permutation matrix. Firstly, the pixel values of a plain image are modified randomly using the binary stream as a key stream. Secondly, the modified image is encrypted again by permutation matrix. The security of encryption scheme is analyzed in detail. And the simulation results show that the proposed scheme has a better efficiency than others´ and a high security performance