Image authentication using soft hashing technique

Designing a hash function for multimedia authentication encompasses many issues like robustness to non- malicious distortion, sensitivity to detect malicious manipulations and security. In this paper, we present an image hashing technique that attempts to simultaneously address the robustness, fragility and security issues. This scheme is an improved version of our previously proposed scheme [1] with a wavelet-based smoothening to improve robustness against JPEG compression and a modified intensity-transformation for enhancing the security. Several experimental results are presented to demonstrate the effectiveness of the proposed scheme.