Image encryption with compound chaotic sequence cipher shifting dynamically

We design a new two-dimensional chaotic function using two one-dimensional chaotic functions, and then prove the chaotic properties to a new function based on a strict Devaney definition. And we propose a new encrypting image scheme using the new compound chaotic function by choosing one of the two one-dimensional chaotic functions randomly. We give statistical analysis, sequence random analysis, and sensitivity analysis to plaintext and key on the proposed scheme. The experimental results show that the new scheme has a very fast encryption speed and the key space is expanded and it can resist all kinds of cryptanalytic, statistical and brute-force attacks, and especially, our new method can be also used to solve the problem that is easily exposed to chosen plaintext attack and low digitization of one-dimensional chaotic function. (c) 2007 Elsevier B.V. All rights reserved.