Jessica Fridrich, a researcher at Binghamton University (and the inventor of speed cubing!) has reportedly filed two patents for technologies that would allow to determine which camera a digital photo has been shot with. Due to tiny irregularities in the production process and in the imaging-chips themselves, every camera produces a random, yet unique noise pattern, the scientists claim. These patterns could be used in forensics to determine whether an image was taken with the same cam, given that two or more pictures or the device itself are available for testing.
This would add yet another to the almost traditional links between cameras and guns because it resembles very much the method of ballistic fingerprinting with which the gun a bullet was fired from can be identified. Law enforcement have already expressed their needs for such a software, since it would enable them to identify the sources of pictures on the web to some extent. But just in cases of illegal porn, of course.
Related: The cellphone forensics kit.