Digital Forensics to Authenticate Digital Photos

My post entitled The Electronic Crime Scene on June 27, 2005, discussed some of the challenges digital electronics generally pose to investigators. Then in my post entitled Recognizing Fake Photos, on August 22, 2005, I reported how digital imagery had created some serious concerns for photojournalists and their editors, judges, and investigators.

Now the Tuesday, December 6, 2005, issue of MIT's Technology Review discusses how "digital forensics can detect misleading cut-and-paste jobs and match a photograph to an individual camera's 'fingerprint.' " The article is entitled Photo Chop Shop.

The article briefly mentions digital watermarking as one means to transparently mark an image to detect tampering. Digital watermarking is not new, but it is somewhat costly.

More fascinating to investigators, though, is the newly developed technique to associate a particular digital camera to a particular image. The simple explanation is that each digital electronic camera has a unique electronic signature that is incorporated into each image that camera produces. Any disturbance to the digital signature suggests image alteration. This, by the way, is one example of measurements and signatures intelligence.

This new technology reported by MIT needs to be evaluated by the criminal justice community as one possible way of overcoming the mistrust of digital imagery by the courts.