Schema for digital image scrambling based on TD-ERCS chaotic sequences
Yan Duan · Jisuanji gongcheng yu sheji · 2008
TD-ERCS is a special chaotic system devised for the chaotic encryption theory.The tangent-delay operation on the physical model of ellipse reflecting cavity is proposed to change the evolution route of the system,and a new class of discrete chaotic map system is deduced.The chaotic sequences meet the security characteristics of chaotic systems without weak key which is generated by weak pe-riod.Scrambling operation is one of protected methods for digital image.This schema is an image chaotic algorithm with shuffling the positions and changing the energy of the image.An address index list could be created by the discrete TD-ERCS chaotic sequences to scramble the positions of the image pixels in the spatial domain by one-way,meanwhile,keys could be computed to transform the DC coefficients of the image which avoid changing the grey values of pixels one by one.The combined algorithm not only enhances the system complexity and security,but also avoids the iterative application of one key and the transmission of multi-key.