Cultivating a robust and efficient quantum-safe HTTPS

Chrome announces the development and phased rollout of Merkle Tree Certificates (MTCs) and a Chrome Quantum-resistant Root Store (CQRS) to enable scalable, bandwidth-efficient post-quantum HTTPS. The blog explains MTC benefits (compact Merkle proofs and CT-like transparency), describes a three-phase deployment (Phase 1 feasibility testing with Cloudflare, Phase 2 CT log operator bootstrapping, Phase 3 CQRS and CA onboarding), and outlines policy and operational priorities—such as ACME-only workflows, improved revocation mechanisms, reproducible domain control validation, and stronger monitoring—while maintaining support for existing roots during the transition.