Application of Threshold Secret Sharing to Image Authentication and Recovery

Abstract

The proposed method borrowed the concept of threshold secret sharing to propose an image recovery scheme. The recovery message of each image block was split into three shares and spread out over the image. When a tampered block needs to be repaired, gathering at least two shares can reconstruct the recovery message. The main merit is that each tampered block has second chance for recovery; moreover, the length of recovery message carried by each pixel can be shortened. As regards to the image authentication, we employed Hsu and Tu’s scheme, which has low false detection rate. To increase the quality of recovery images, we add a third stage on Hsu and Tu’s scheme to decrease false negative rate. The experiment results show the proposed scheme can detect the tampering with low false negative rate and recover the tampered image with good quality.