cloudflare/circl

Health v2 · maintenance only

Flags: no_license

Adoption not part of the score

1710 stars · 219 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

CIRCL is Cloudflare's Go library of cryptographic primitives covering post-quantum algorithms (ML-KEM/Kyber, ML-DSA/Dilithium, SIKE/CSIDH), elliptic-curve cryptography (X25519, Ed448, BLS12-381), and protocols like HPKE and blind signatures. It is intended for experimental deployment and standardization work, with some packages not fully constant-time.

Use cases

• add post-quantum key exchange to a Go application
• implement hybrid TLS with ML-KEM
• sign and verify with ML-DSA / Dilithium
• use HPKE for encrypted payloads in Go
• experiment with elliptic curves like FourQ and BLS12-381
• prototype blind signature schemes
• evaluate FIPS 203/204 algorithms before standard adoption

When to choose

• you need post-quantum or advanced ECC primitives in Go not available in the standard library
• you are prototyping standards-track cryptography or PQ TLS experiments
• you want a maintained library from an experienced cryptography team

When to avoid

• you need a fully audited, guaranteed constant-time library for production secrets - some packages leak timing
• you need API stability - the library warns its API may change
• you work outside the Go ecosystem

Facets

library · maturity active

cryptography security sdk security developer-tools privacy go cross-platform post-quantum elliptic-curves ml-kem ml-dsa kyber dilithium hpke ed25519 pki constant-time

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