SYSTEM Cited by 1 source
CIRCL (Cloudflare Interoperable Reusable Cryptographic Library)¶
What¶
CIRCL (github.com/cloudflare/circl) is Cloudflare's open-source Go cryptography library providing implementations of post-quantum and advanced cryptographic algorithms that Go's standard library does not yet support.
Role in PQ authentication¶
When Cloudflare's SSL/TLS control-plane service (written in Go) needed
to parse and validate ML-DSA certificates for the Authenticated Origin
Pulls and Custom Origin Trust Store products, Go's standard crypto/x509
and crypto/tls libraries did not yet support ML-DSA. Cloudflare
implemented the necessary functionality
in CIRCL to patch in support — ML-DSA X.509 certificate parsing and
validation.
Planned deprecation (Go 1.27)¶
Go 1.27 (expected August 2026) will include native ML-DSA support in the standard library, allowing Cloudflare to drop the CIRCL dependency for ML-DSA cert handling. The post notes this is a "relatively simple change" for one service, but "repeating this for every service that needs post-quantum authentication support would be a major chore" — hence the value of waiting for stdlib support for broader rollout.
(Source: sources/2026-07-29-cloudflare-post-quantum-authentication-to-origins)
Seen in¶
- sources/2026-07-29-cloudflare-post-quantum-authentication-to-origins — CIRCL PR #559, ML-DSA X.509 parsing for AOP/COTS control plane.
Related¶
- systems/boringssl — data-plane TLS library (Rust/C side)
- systems/ml-dsa-signature — the algorithm CIRCL now supports
- concepts/post-quantum-authentication — the use case