Outside Looking In: Approaches to Content Moderation in End-to-End Encrypted Systems

Understand

In this paper, we assess existing technical proposals for content moderation in End-to-End Encryption (E2EE) services.

• First, we explain the various tools in the content moderation toolbox, how they are used, and the different phases of the moderation cycle, including detection of unwanted content.
• We then lay out a definition of encryption and E2EE, which includes privacy and security guarantees for end-users, before assessing current technical proposals for the detection of unwanted content in E2EE services against those guarantees.
• We find that technical approaches for user-reporting and meta-data analysis are the most likely to preserve privacy and security guarantees for end-users.