Chaotic Maps Based Scheme for Image Authentication

In this paper a watermarking scheme for image authentication using the chaotic maps is proposed. Depending on the contents of the 2 x 2 image block, Arnold’s Cat map iterations are used to generate the block authentication watermark bits. As the authentication bits are block content dependent, any changes to the content affects the authentication bits. The watermark bits are then embedded in the 3 LSBs of the block. The experimental results show that the tamper localisation capacity of the scheme under various attacks such as object insertion, deletion and vector quantization attacks is superior to some of the recently proposed schemes.