Image authentication for digital image evidence
Che‐Yen Wen, Kun-ta Yang · 2006
With the increasing use of digital images in forensic science, it is obviously that digital images captured from CCD (chargecoupled device) cameras or other digital image devices have become direct or indirect exhibit in court to demonstrate the relationship between suspects and the criminals. To keep the integrity and ensure the accuracy and reliability of the standard operating procedures (SOPs), all processing steps (such as parameters, mathematical actions and processed images) have to be documented or recorded by forensic examiners. However, the easy manipulation property of digital images makes us doubtful when using digital images as evidence in court. In order to improve this situation, we need a robust method to guarantee and strengthen chain of custody. In this paper, we propose a cryptography based technology that has been publicly applied in information security to assist the examination and analysis of digital image data. From our experimental results, the technology provides a unique cipher for every single processed image. We can use the unique cipher (check any change of the cipher) to confirm if the image is modified easily. With the proposed technology, we can strengthen image authentication effectively.