Applying public-key watermarking techniques in forensic imaging to preserve the authenticity of the evidence

Abstract

The traditional verifying evidence method in court is to check the integrity of the chain of custody of evidence. However, since the digital image can be easily transferred by Internet, it is not easy for us to keep the integrity of the chain of custody. In this article, we use the PKI (Public-Key Infrastructure), Public-Key Cryptography and watermark techniques to design a novel testing and verifying method of digital images. The main strategy of the article is to embed encryption watermarks in the least significant bit (LSB) of digital images. With the designed method, we can check the integrity of digital images by correcting public-key without side information and protecting the watermarks without tampering or forging, even the embedded method is open. Finally the proposed method can be applied in court to digital evidence testing and verification, and used to check the admissibility of digital image. © 2008 Springer-Verlag Berlin Heidelberg.