HTTPS certificates in the age of quantum computing

2 days ago

The IETF is working on post-quantum cryptography for HTTPS certificates to protect against future quantum computing threats.
Current focus includes key exchange and authentication, with certificates potentially growing 40 times larger due to post-quantum signatures.
Post-quantum signatures like ML-DSA-44 are much larger than traditional ones, increasing bandwidth and latency for web connections.
A new IETF working group, PLANTS, proposes using Merkle trees and append-only issuance logs to reduce certificate size and improve efficiency.
PLANTS suggests replacing traditional certificate chains with proofs of inclusion in issuance logs, reducing redundancy and overhead.
Merkle trees allow batching certificates into a single signed tree, minimizing the number of signatures needed.
Google plans to evaluate Merkle-tree-based certificates in Chrome by 2027, with broader adoption expected by 2029-2030.
The protocol's success depends on clients staying updated to benefit from smaller, signatureless certificates.
Post-quantum certificate adoption is expected well before quantum computers pose a real threat to authentication security.

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