Image integrity and authenticity verification via content-based watermarks and a public key cryptosystem
Chang‐Tsun Li, L. Der-Chyuan, Jiaug-Luna Liu · Warwick Research Archive Portal (University of Warwick) · 2003
A technique using the inherent feature map of the underlying image as the watermark is proposed in this work. First, on the transmitting side a binary feature map is extracted as watermark and partitioned into blocks. Secondly, to create a watermarked image, neighboring feature map/watermark blocks are blended and encrypted for insertion. On the receiving side, the feature map from the received image is extracted again and compared against the recovered watermark to verify the integrity and authenticity. In addition to the capability of detecting geometric transformation, removal of original objects and addition of foreign objects, the proposed scheme is also capable of localizing tampering and detecting cropping without a priori knowledge about the image. This work can be applicable in the areas of military imagery transmission, imaging of micro evidence in the criminal scene, and medical image archiving. Key words: Digital watermarking, cryptosystem, information security I.