Crate reach_signatures

Reach Signatures

This crate provides a dual-signature scheme combining classical Ed25519 elliptic curve signatures with post-quantum FN-DSA lattice-based signatures. Both signatures must be valid for authentication to succeed, providing security against both classical and quantum computer attacks.

It uses SHA3-512 for digest generation and provides context-aware signing using type names for domain separation.

Core Traits

• Digestible: Convert data structures to SHA3-512 digests for signing
• Signable: Types that can be signed and converted to their signed variants
• Sign: Signing key operations with both EC and PQ algorithms
• Verifier: Provides verifying keys for operations with verifiable data structures
• Verifiable: Types that carry signatures and can be verified

The crate is designed to work across different Reach components including Reaching Link, Reachable Secrets, and the Reach Attestant.

Constants

FN_DSA_SIGNATURE_EMPTY

Zero filled array with the size of an FN-DSA signature.

FN_DSA_SIGNING_EMPTY

Zero filled array with the size of an FN-DSA signing key.

Traits

Digestible

Convert data structures to SHA3-512 digests.

Sign

Signing key operations.

Signable

Sign and convert to the respective signed variant.

Signatures

Carries signatures.

Verifiable

Verifiable if Digestible and carrying Signatures.

Verifier

Provides verifying keys for signature verification operations.

Verifies

Indicating which types can be verified by a given verifier.

VerifyingKeys

Links signing keys to their corresponding verifying keys.

Functions

verify_digest

Verify both Ed25519 and FN-DSA signatures with a digest.