Computational Sensor Fingerprints

Analysis of imaging sensors is one of the most reliable photo forensic techniques, but it is increasingly challenged by complex image processing in modern cameras. The underlying photo response non-uniformity (PRNU) is distilled into a static sensor fingerprint unique for each device. This makes it easy to estimate and spoof and limits its reliability in face of sophisticated attackers. We propose to exploit computational capabilities of emerging intelligent vision sensors to design next-generation
computational sensor fingerprints
. Such sensors allow for running neural network inference directly on raw pixels, which enables end-to-end optimization of the entire photo acquisition and distribution pipeline. Control over fingerprint generation allows for adaptation to various requirements and threat models. In this study we provide a detailed assessment of security properties and evaluate two approaches to prevent spoofing: fingerprint generation based on local image content and adversarial training. We found that adversarial training is currently impractical, but content fingerprints deliver good performance in the considered cross-domain (RAW-RGB) setting and could provide robust best-effort protection against photo manipulation. Moreover, computational fingerprints can alleviate other limitations of PRNU, e.g., its limited reliability for dark/texture content and expensive fingerprint storage that hinders scalability. To enable this line of work, we developed a novel open-source and high-fidelity simulation environment for modeling photo acquisition and distribution pipelines (
https://github.com/pkorus/neural-imaging
).