Key Transparency closes one of the most important gaps in modern end-to-end encryption: it lets users verify that the public keys they use for encryption actually belong to the users they’re talking to. For too long, KT was either omitted by end-to-end encrypted services or accomplished through a custom protocol. The IETF is now standardizing a protocol, and this talk is a practical guide for anyone considering adopting it.
The first portion of the talk covers the high-level security and privacy properties that the IETF protocol provides and the pitfalls we often hit trying to reach them: optional rather than mandatory trusted third parties, rapid updates, and efficient user auditing, all while strongly protecting user privacy. The second portion turns to more practical deployment considerations: the differences between the draft’s deployment modes, designing applications that rely on credentials vs interactive lookups, compliance with privacy regulation, and headline numbers for proof size, throughput, and storage.
Speaker
Brendan is a freelance cryptography engineer who focuses on developing and deploying standards that make the whole Internet safer. His experience includes building the first major TLS 1.3 deployment at Cloudflare and operating Certificate Transparency logs that are trusted in Chrome.
