On the Security and Applicability of Fragile Camera Fingerprints

TL;DR

This paper analyzes the security of fragile camera fingerprints, which leverage data asymmetry to enable reliable device identification even under compression attacks, with implications for digital image forensics.

Contribution

It provides the first systematic analysis of fragile camera fingerprints' security, combining theoretical and practical tests to evaluate their robustness against adversarial compression.

Findings

Fragile fingerprints enable reliable identification at common compression levels.

The security of fragile fingerprints is supported by theoretical and empirical evidence.

Fragile fingerprints exploit data asymmetry to resist certain attacks.

Abstract

Camera sensor noise is one of the most reliable device characteristics in digital image forensics, enabling the unique linkage of images to digital cameras. This so-called camera fingerprint gives rise to different applications, such as image forensics and authentication. However, if images are publicly available, an adversary can estimate the fingerprint from her victim and plant it into spurious images. The concept of fragile camera fingerprints addresses this attack by exploiting asymmetries in data access: While the camera owner will always have access to a full fingerprint from uncompressed images, the adversary has typically access to compressed images and thus only to a truncated fingerprint. The security of this defense, however, has not been systematically explored yet. This paper provides the first comprehensive analysis of fragile camera fingerprints under attack. A series of theoretical and practical tests demonstrate that fragile camera fingerprints allow a reliable device identification for common compression levels in an adversarial environment.