Stego optical encryption based on chaotic S-box transformation

In this article, an optical image encryption algorithm with an information hiding technique is presented. In this algorithm, a secret image is implanted into the cover image. After that the stego-image is encrypted with the help of double random phase encoding algorithm and chaotic substitution box transformation. Also, we present a comparative analysis between images "without substitution box transformation", "with substitution box transformation" and "with chaotic substitution box transformation". Security test shows that image transform with chaotic substitution box transformation is better than others. Furthermore we analyze proposed encryption scheme with other existing techniques and come to close that our algorithm is better than others. (C) 2014 Elsevier Ltd. All rights reserved.