A Watermarking-Based Authentication with Malicious Detection and Recovery

In this paper, a watermarking-based image authentication scheme used to verify the contents of transmission grayscale images is proposed. In this scheme, the watermark of one given image is generated from both frequency domain and spatial domain. First, the number of encoding stages of each DWT coefficient during the multi-stage encoding is taken as frequency watermark. Second, the mean values of blocks are stored as spatial watermark. The watermark is then embedded into SPIHT encoded list of significant pixels (LSP) bit stream. By comparing the embedded watermark and the corresponding message extracted from decoded image to be authenticated, the given image can then be authenticated. The experimental results show that the proposed scheme can distinguish acceptable operations from malicious manipulations. Furthermore, the positions of intended modified areas can be located accurately and recovered approximately