How We’re Building Scam Alert on WhatsApp With End-to-End Encryption and Verifiability Guarantees
Aug 12, 2026
Summary
This post details the technical implementation of WhatsApp's new Scam Alert feature, which uses an on-device machine learning model to detect potential scam messages. It emphasizes end-to-end encryption and verifiability guarantees, outlining design principles such as on-device processing, no automatic reporting, and user control. The technical implementation focuses on privacy-preserving analytics using confidential federated analytics pipelines built on Trusted Execution Environments (TEEs) and differentially private aggregates for telemetry. It also details verifiable model behavior through public transparency ledgers and model weight publication.
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