Experimental Analyses of the Physical Surveillance Risks in Client-Side Content Scanning
Ashish Hooda
Network and Distributed System Security (NDSS) Symposium 2024 · Day 1 · Adversarial ML
The proliferation of end-to-end encryption (E2EE) in digital communication platforms, while a boon for user privacy, has presented a significant challenge for detecting and mitigating the spread of illicit content, such as child sexual abuse material (CSAM). To circumvent this, Client-Side Image Scanning (CSIS) has emerged as a proposed solution, where content is scanned directly on a user's device *before* encryption. These systems employ **perceptual hashing algorithms** like PhotoDNA or PDQ to identify visually similar images against a database of known illicit content, theoretically preserving privacy by only matching hashes.