Abstract: In order to ensure the security of image effectively, a nd aiming at the deficiency of current image encryption algorithm, we designed a n image encryption algorithm based on combined chaotic syst em. Firstly, logistic chaotic system was used to process original plaintext image and scramble pixel position of imag e to carry out image block scramble processing, and then Henon chaotic sys tem was used to encrypt image pixel after block processing, thus realizing the p ixel value scrambling. The performance of image encryp tion was tested by simulation experiments. Test results show that, using the enc ryption algorithm, the correlation of adjacent pixels is small, and it has reliable transmission security. It can encrypt the image information, increase the ke y space, and improve the image of various anti attack ability.

Key words: anti attack ability,  image security, chaotic system, Logistic map, image encryption