Rate-universal Digital Image Encryption and Against Shearing Attacks Recovery Algorithm

In order to protect digital image,a universal encryption and decryption algorithm based on chaotic system and its chaotic sequence is proposed.Firstly,according to the key,a chaotic sequence is generated.After generating a corresponding subscript sequence by sorting it,scrambling encryption of pixel coordinates based on the subscript sequence will be realized.Then,according to the sub-key and the image type value,an unsigned integer sequence is generated from the chaotic sequence.After that,pixel permutation encryption will be realized by using the XOR operation between the unsigned integer sequence and each corresponding pixel value in turn.In allusion to the malicious shearing attack,an against shearing attack recovery algorithm based on neighboring pixels characteristic is presented simultaneously.Experimental results and theoretical analysis show that the algorithm has good encryption effect,a large space of key,a strong security and universality,more desirable ability of against statistical analysis and shearing attacks.