AuSR3: A new block mapping technique for image authentication and self-recovery to avoid the tamper coincidence problem

Abstract

This paper proposes a new block mapping technique for image authentication and self-recovery designed to avoid the tamper coincidence problem called the AuSR3. The tamper coincidence problem can arise when modifications to an image affect the original block and its recovery data, resulting in the inability to recover the tampered region of the image. The new block mapping technique ensures that the recovery data of a block is embedded into the most distant location possible, minimizing the tamper coincidence problem. In addition, the improved LSB shifting algorithm is employed to embed the watermark data consisting of authentication and recovery data. The experimental result shows that the AuSR3 can produce high-quality watermarked images across various datasets with average PSNR values of 46.2 dB, which improved by 2.1 dB compared to the LSB replacement technique. The new block mapping technique avoids the tamper coincidence problem by up to 25% tampering rates. It contributes to the high-quality recovered image with a PSNR and SSIM value of 39.10 dB and 0.9944, respectively, on a 10% tampering rate on the USC-SIPI dataset.