摘要

This paper proposes several image encryption schemes for popular image formats as Joint Photographic Experts Group (JPEG), Graphics Interchange Format (GIF), Portable Network Graphics (PNG), and Tagged Image File Format (TIFF). A cross chaotic map proposed based on Devaney's theory and dynamic block dividing of the 3D baker using the cross chaotic map are used for diffusion and permutation in encryption. Moreover, in order to verify user's identity, authentication is carried out using information hiding based on the cross chaotic function. In our methods, image files syntax and structure are not destructed, and the original image can be recovered lossless. For GIF, it keeps the property of animation successfully. The security test results indicate the proposed methods have high security, and the speed of our algorithm is faster than classical solutions. JPEG, GIF, TIFF and PNG image formats are popular contemporarily. Therefore this paper shows that the prospect of chaotic image encryption is promising.

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