FROST (Flexible Round-Optimised Schnorr Threshold signatures)

Rust implementations of 'Two-Round Threshold Schnorr Signatures with FROST'.

Unlike signatures in a single-party setting, threshold signatures require cooperation among a threshold number of signers, each holding a share of a common private key. The security of threshold schemes in general assume that an adversary can corrupt strictly fewer than a threshold number of participants.

'Two-Round Threshold Schnorr Signatures with FROST' presents a variant of a Flexible Round-Optimized Schnorr Threshold (FROST) signature scheme originally defined in FROST20. FROST reduces network overhead during threshold signing operations while employing a novel technique to protect against forgery attacks applicable to prior Schnorr-based threshold signature constructions. This variant of FROST requires two rounds to compute a signature, and implements signing efficiency improvements described by Schnorr21. Single-round signing with FROST is not implemented here.

Status ⚠

The FROST specification is not yet finalized, and this codebase has not yet been audited or released. The APIs and types in frost-core are subject to change.

Usage

frost-core implements the base traits and types in a generic manner, to enable top-level implementations for different ciphersuites / curves without having to implement all of FROST from scratch. End-users should not use frost-core if they want to sign and verify signatures, they should use the crate specific to their ciphersuite/curve parameters that uses frost-core as a dependency.

Developer Information

Pre-commit checks

1. Run tests cargo test
2. Run formatter cargo fmt
3. Check linter cargo clippy --all-features --all-targets -- -D warnings and if you want to automatically fix then run cargo clippy --fix

Coverage

Test coverage checks are performed in the pipeline. This is cofigured here: .github/workflows/coverage.yaml To run these locally:

1. Install coverage tool by running cargo install cargo-llvm-cov
2. Run cargo llvm-cov --ignore-filename-regex '.*(tests).*|benches.rs|gencode|helpers.rs (you may be asked if you want to install llvm-tools-preview, if so type Y)