Cloudflare helps verify the security of end-to-end encrypted messages by auditing key transparency for WhatsApp

What this post added

This post details Cloudflare's new role in verifying WhatsApp's Key Transparency audit proofs. It describes the architecture of the Auditor service built on Cloudflare Workers, utilizing Rust and Durable Objects for timestamping and R2 buckets with containers for tree validation. The contribution focuses on building and operating a system that audits the Auditable Key Directory (AKD) to ensure the global uniqueness and validity of epochs, thereby enhancing the security of end-to-end encrypted messages.