Discrete Wavelet Transform based Watermarking for Image Content Authentication

A watermarking scheme based on discrete wavelet transform for content based image authentication is proposed in this paper. The proposed scheme is tolerant to minor modifications which could be due to legitimate image processing operations. The tolerance is obtained by protecting the low frequency data of the wavelet transform using approximate message authentication codes. Major modifications in the image content are identified as forgery attacks. Simulation results are given for unintentional modifications, such as channel noise, and for intentional modifications such as the object insertion and deletion. Security analysis is given at the end to analyze the security strength of the proposed image authentication scheme.