SARI: self-authentication-and-recovery image watermarking system

Abstract

In this project, we designed a novel image authentication system based on a our semi-fragile watermarking technique. The system, called SARI, can accept quantization-based lossy compression to a determined degree without any false alarm and can sensitively detect and locate malicious manipulations. It's the first system that has such capability in distinguishing malicious attacks from acceptable operations. Furthermore, the corrupted area can be approximately recovered by the information hidden in the other part of the contentimage. The amount of information embedded in our SARI system has nearly reached the theoretical maximum zero-error information hiding capacity of digital images. The software prototype includes two parts - the watermark embedder that's freely distributed and the authenticator that can be deployed online as a third-party service or used in the recipient side.