CT: Authenticating Reality

Authenticating Reality 0627645 Digital photography is a poor way to authenticate reality because digital photographs are notoriously easy to manipulate and falsify. This same unreliability applies to other digital media: voice recordings can be spliced and synthesized and digital manipulation of movies is a high art. Nonetheless, it is people's nature to believe what they see and hear, and falsified digital recordings are frequently used to influence public opinion. Doctored images of political figures, scientific and legal evidence, and news and current events are commonplace. This project explores new technologies, based on cryptographic hardware, advanced digital signature schemes, and computer-vision techniques, to enable users to verify the authenticity of digital photographs and other media. With tamper-proof cryptographic hardware embedded in digital cameras, photographers can produce photos along with proof of their authenticity. By employing homomorphic signature schemes, photographers and editors can perform necessary scaling and cropping on those images while maintaining the proof of authenticity. By authenticating other internal state of the camera when the picture is taken, we can strengthen existing machine-vision fraud-detection algorithms and enable new ones. This project may revolutionize the way society values and uses photographic and other digital evidence. The research serves the interests of all scientific disciplines --- not just computer security --- as well as the disciplines of law, economics, and journalism.