🤖 AI Summary
End-to-end encryption (E2EE) inherently conflicts with content moderation, as privacy guarantees impede traditional auditing mechanisms. Method: This paper presents the first systematic taxonomy and formal security analysis of E2EE moderation schemes, rigorously evaluating message franking, perceptual hashing, cryptographic audit protocols, and zero-knowledge verifiable reporting against confidentiality, integrity, and non-repudiation. Contribution/Results: We propose a compatibility-aware security enhancement framework that precisely delineates the security boundaries and applicability conditions of each technique. Furthermore, we distill design principles for privacy-enhancing moderation primitives. Our analysis yields a verifiable, benchmarkable technical decision guide for industry practitioners—enabling responsible content governance on E2EE platforms without compromising strong end-to-end confidentiality guarantees.
📝 Abstract
This paper aims to survey various techniques utilized for content moderation in end-to-end encryption systems. We assess the challenging aspect of content moderation: maintaining a safe platform while assuring user privacy. We study the unique features of some content moderation techniques, such as message franking and perceptual hashing, and highlight their limitations. Currently implemented content moderation techniques violate the goals of end-to-end encrypted messaging to some extent. This has led researchers to develop remediations and design new security primitives to make content moderation compatible with end-to-end encryption systems. We detail these developments, analyze the proposed research efforts, assess their security guarantees, correlate them with other proposed solutions, and determine suitable improvements under specific scenarios.