ecc - Elliptic Curve Groups

  import "github.com/bytemare/ecc"

High-level Go wrapper for multiple elliptic curve groups. The package unifies scalar, element, and hash-to-curve (RFC 9380) operations behind a single API so callers can swap groups with minimal code changes while relying on common and secure backends of well-maintained cryptographic libraries.

You don't have to care about the parameters and the specifics of each group or backend. Simply pick a Group identifier to get scalars and elements and perform operations.

Elliptic Curve Groups

The following table shows supported groups with hash-to-curve capability and links each one to the underlying implementations:

ID	Name	Prime-order	Backend	Encoding Endianness
1	Ristretto255	✓	github.com/gtank/ristretto255	little-endian
3	P-256	✓	filippo.io/nistec	big-endian
4	P-384	✓	filippo.io/nistec	big-endian
5	P-521	✓	filippo.io/nistec	big-endian
6	Edwards25519	✗ (cofactor 8)	filippo.io/edwards25519	little-endian
7	Secp256k1	✓	github.com/bytemare/secp256k1	big-endian

Some identifiers are reserved for future use, waiting for compatible, stable, and secure implementations to become available (e.g. Curve25519, Decaf448, Double-Odd).

Documentation

You can find the documentation and usage examples in the package doc and the project wiki.

Identity / Point at infinity

Encoding may succeed (e.g., all‑zeros on some curves), but do not feed identity encodings back into decoders. Decoding the identity/infinity element is rejected across all groups except NIST curves.

Domain Separation Tags (DST)

DSTs must not be empty, and are recommended to tbe longer than 16 bytes. You can build DSTs with Group.MakeDST(app, version), which include the group and ciphersuite identifier.

Versioning

Releases follow Semantic Versioning.

---

Release Integrity (SLSA Level 3)

Releases are built with the reusable bytemare/slsa workflow and ship the evidence required for SLSA Level 3 compliance:

• 📦 Artifacts are uploaded to the release page, and include the deterministic source archive plus subjects.sha256, signed SBOM (sbom.cdx.json), GitHub provenance (*.intoto.jsonl), a reproducibility report (verification.json), and a signed Verification Summary Attestation (verification-summary.attestation.json[.bundle]).
• ✍️ All artifacts are signed using Sigstore with transparency via Rekor.
• ✅ Verification (or see the latest docs at bytemare/slsa):

curl -sSL https://raw.githubusercontent.com/bytemare/slsa/main/verify-release.sh -o verify-release.sh
chmod +x verify-release.sh
./verify-release.sh --repo <owner>/<repo> --tag <tag> --mode full --signer-repo bytemare/slsa

Run again with --mode reproduce to build in a container, or --mode vsa to validate just the verification summary.

Contributing and Feedback

Use GitHub Issues for bug reports, feature requests, and general feedback. If you have questions about contributing, start with CONTRIBUTING.md.

In docs/ you can also find:

• Architecture and engineering guidelines: docs/architecture_and_guidelines.md
• Security assurance and threat model: docs/secure_design.md
• Roadmap and longer-term goals: docs/roadmap.md
• Governance and releasing processes: docs/governance.md, docs/releasing.md

License

This project is licensed under the MIT License.

Citation

If you use this package in academic work, please cite it via CITATION.cff.