Semi-Fragile Watermarking for Image Authentication with High Tampering Localization Capability

In this paper we propose a novel watermarking scheme for image authentication. A high localization of tampering detection is achieved by applying a random permutation process where every embedded watermark bit verifies random image positions instead of a local image block. Thereby the resolution of tampering detection is significantly improved in comparison to existing solutions while keeping the payload low. Furthermore, the proposed scheme doesn´t embed the watermark locally but distributes it into the suitable embedding wavelet coefficients, avoiding embedding in smooth regions. Therefore, the scheme is intrinsically secure to block-based local attacks and retains high fidelity of the watermarked image. Scalable sensitivity of tampering detection is enabled in the authentication process. Analysis and experimental results demonstrate the performance and effectiveness of the scheme for image authentication