Region-aware Photo Assurance System for Image Authentication

Abstract

Zero-knowledge Proof (ZKP) allows active image authentication to prove image integrity after editing without revealing its source. However, existing ZKP solutions require impractical execution time, leaving a considerable gap between theory and practice. To tackle this, we present a Region-Aware Photo Assurance System based on the nature of image editing with privacy: sensitive information is usually local and relatively small, and thus by cropping and/or adding mosaic to these small regions suffices to protect privacy. Using ZKP for the locally edited region and digital signature for the others can still ensure the integrity of an image, with significantly better efficiency. We comprehensively analyzed the system's performance and showed the advantage of our system compared with the state-of-the-art ZKP-based method, PhotoProof, with 15x/60xfaster on the KeyGen/Proof operations and 25x lower in the Proof size. Furthermore, we protect several real-world images selected in the Redaction dataset with our system. Our system achieves up to 2,700x faster than PhotoProof for a proof generation. We expect the system can become a practical system for real-world applications.