
10/28/2025 · Luke Valenta, Christopher Patton, Vânia Gonçalves, Bas Westerbaan
What this post added
Introduces Merkle Tree Certificates (MTCs) as a proposal to redesign the WebPKI for post-quantum cryptography. MTCs aim to reduce the number of signatures and public keys in TLS handshakes to enable the deployment of quantum-safe certificates without performance degradation. The post details the current WebPKI's limitations with larger PQ signatures and outlines the MTC approach, which includes disseminating necessary information out-of-band and making certificate transparency a first-class feature. Cloudflare is also announcing an experimental deployment of MTCs in collaboration with Chrome Security.