Compensated Signature Embedding for Multimedia Content Authentication

Abstract

One of the main goals of digital content authentication and preservation techniques is to guarantee the originality and quality of the information. In this article, robust watermarking is used to embed content-based fragile signatures in multimedia signals to achieve efficient authentication without requiring any third-party reference or side information. To overcome the signature alteration caused by the embedding perturbation and other possible encoding operations, a closed-form compensation technique is proposed for ensuring signature consistency by employing a Lagrangian-based approach. A minimum distortion criterion is used to ensure signal quality. The effectiveness of the proposed approach is investigated with simulations of examples of image authentication in which signatures are designed to reveal tamper localization. Results using quantitative performance criteria show successful authentication over a range of robustness in embedding watermarks using both QIM-DM and spread-spectrum techniques. A comparison with two iterative compensation schemes is also presented.