diff --git a/.gitattributes b/.gitattributes new file mode 100644 index 0000000..dfe0770 --- /dev/null +++ b/.gitattributes @@ -0,0 +1,2 @@ +# Auto detect text files and perform LF normalization +* text=auto diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml new file mode 100644 index 0000000..bb50fb8 --- /dev/null +++ b/.github/workflows/ci.yml @@ -0,0 +1,39 @@ +name: CI + +on: + push: + branches: + - "**" + pull_request: + +jobs: + rust-checks: + name: ${{ matrix.os }} + runs-on: ${{ matrix.os }} + strategy: + fail-fast: false + matrix: + os: + - ubuntu-latest + - macos-latest + + steps: + - name: Checkout + uses: actions/checkout@v4 + + - name: Setup Rust + uses: dtolnay/rust-toolchain@stable + with: + components: rustfmt, clippy + + - name: Cache dependencies + uses: Swatinem/rust-cache@v2 + + - name: Check formatting + run: cargo fmt --all -- --check + + - name: Lint + run: cargo clippy --workspace --all-targets -- -D warnings + + - name: Test + run: cargo test --workspace --all-targets diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..ea8c4bf --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +/target diff --git a/Cargo.lock b/Cargo.lock new file mode 100644 index 0000000..9030937 --- /dev/null +++ b/Cargo.lock @@ -0,0 +1,19 @@ +# This file is automatically @generated by Cargo. +# It is not intended for manual editing. +version = 4 + +[[package]] +name = "curve25519" +version = "0.1.0" + +[[package]] +name = "curve25519-cuda" +version = "0.1.0" + +[[package]] +name = "curve25519-derive" +version = "0.1.0" + +[[package]] +name = "ed25519-heea" +version = "0.1.0" diff --git a/Cargo.toml b/Cargo.toml new file mode 100644 index 0000000..addbf9b --- /dev/null +++ b/Cargo.toml @@ -0,0 +1,11 @@ +[workspace] +members = [ + "curve25519-cuda", + "curve25519", + "curve25519-derive", + "ed25519-heea", +] +resolver = "2" + +[profile.dev] +opt-level = 2 \ No newline at end of file diff --git a/LICENSE-APACHE b/LICENSE-APACHE new file mode 100644 index 0000000..4eca45d --- /dev/null +++ b/LICENSE-APACHE @@ -0,0 +1,201 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. 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IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/README.md b/README.md new file mode 100644 index 0000000..bf0437e --- /dev/null +++ b/README.md @@ -0,0 +1,137 @@ +# curve25519-sol + +A high-performance, opinionated fork of [curve25519-dalek] and [ed25519-zebra] focused on +accelerated Ed25519 signature verification via the **HEEA** (Half-Extended Euclidean Algorithm) +method and a reduced set of well-tested backends. + +> Original library READMEs: [README_dalek.md](README_dalek.md) (workspace) · +> [curve25519/README_dalek.md](curve25519/README_dalek.md) · +> [ed25519-heea/README_zebra.md](ed25519-heea/README_zebra.md) + +--- + +## Crates + +| Crate | Description | +|---|---| +| [`curve25519`](./curve25519) | Fork of `curve25519-dalek`. Core elliptic-curve arithmetic over Curve25519, Edwards, Ristretto, and Short-Weierstrass forms, with HEEA scalar decomposition and a narrowed backend set. | +| [`ed25519-heea`](./ed25519-heea) | Fork of `ed25519-zebra`. ZIP-215-compliant Ed25519 with an added `verify_heea` fast-path that uses HEEA half-size scalars. | +| [`curve25519-cuda`](./curve25519-cuda) | GPU-accelerated multi-scalar multiplication (MSM) via CUDA/SPPARK. Falls back to CPU when CUDA is unavailable. | +| [`curve25519-derive`](./curve25519-derive) | Helper proc-macro crate (`#[unsafe_target_feature]`) inherited from upstream; required to write clean SIMD code. | + +--- + +## Key Changes from Upstream + +### HEEA Signature Verification + +Standard Ed25519 verification checks **sB = R + hA**, where `h` is a 256-bit scalar. +HEEA (from the TCHES 2025 paper _"Accelerating EdDSA Signature Verification with Faster Scalar +Size Halving"_) transforms this into a 4-point MSM with ~128-bit scalars: + +``` +τs_lo · B + τs_hi · (2¹²⁸·B) = τ·R + ρ·A +``` + +where `ρ` and `τ` are half-size (~127-bit) values derived from `h` via a half-extended +Euclidean algorithm, and `τs = τs_hi · 2¹²⁸ + τs_lo`. All four scalars are ≤128 bits, and +two of the bases (`B` and `2¹²⁸B`) use precomputed tables. In practice this yields roughly +**~15% faster** verification compared to the standard double-scalar-multiplication path. + +The algorithm is implemented in: +- [`curve25519/src/scalar/heea.rs`](curve25519/src/scalar/heea.rs) – `curve25519_heea_vartime` +- [`curve25519/src/traits.rs`](curve25519/src/traits.rs) – `HEEADecomposition` trait +- [`curve25519/src/backend/serial/scalar_mul/vartime_triple_base.rs`](curve25519/src/backend/serial/scalar_mul/vartime_triple_base.rs) – optimised 128+128+256 MSM +- [`ed25519-heea/src/verification_key.rs`](ed25519-heea/src/verification_key.rs) – `VerificationKey::verify_heea` + +### Reduced Backend Set + +Upstream `curve25519-dalek` supports serial, fiat-crypto, AVX2, and unstable AVX512 backends. +This fork retains only the backends actively tested and maintained here: + +| Backend | Platform | Selection | +|---|---|---| +| `serial` | All (macOS, Linux, …) | Automatic fallback | +| `simd` / AVX2 | x86-64 with AVX2 | Runtime CPU detection | +| CUDA (separate crate) | NVIDIA GPU | Opt-in via `curve25519-cuda` | + +The `fiat` (formally-verified) and `unstable_avx512` backends have been removed to reduce +maintenance surface. If you need them, use upstream `curve25519-dalek` directly. + +--- + +## Usage + +Add the relevant crate to `Cargo.toml`: + +```toml +# Core curve arithmetic with HEEA +curve25519-sol = { git = "https://github.com/zz-sol/ed25519-sol" } + +# Ed25519 signatures with fast HEEA verification +ed25519-heea = { git = "https://github.com/zz-sol/ed25519-sol" } +``` + +### Standard Ed25519 verification + +```rust +use ed25519_heea::{SigningKey, VerificationKey}; +use rand::thread_rng; + +let msg = b"hello world"; +let sk = SigningKey::new(thread_rng()); +let sig = sk.sign(msg); +let vk = VerificationKey::from(&sk); + +// Standard ZIP-215-compliant verification +vk.verify(&sig, msg).expect("valid signature"); +``` + +### HEEA-accelerated verification + +```rust +// Fast path: ~15% faster via half-size scalars (same result) +vk.verify_heea(&sig, msg).expect("valid signature"); +``` + +--- + +## Building + +```sh +# Standard build +cargo build --release + +# With AVX2 (automatic on x86-64 at runtime; or force compile-time) +RUSTFLAGS='-C target-feature=+avx2' cargo build --release + +# Run benchmarks +cargo bench --features "rand_core" -p curve25519 +cargo bench -p ed25519-heea +``` + +--- + +## References + +- [Accelerating EdDSA Signature Verification with Faster Scalar Size Halving](https://tches.iacr.org/index.php/TCHES/article/view/11971) — TCHES 2025 +- [ZIP 215](https://zips.z.cash/zip-0215) — Ed25519 validation rules used by Zcash +- [curve25519-dalek](https://github.com/dalek-cryptography/curve25519-dalek) — upstream curve library +- [ed25519-zebra](https://github.com/ZcashFoundation/ed25519-zebra) — upstream signature library + +--- + +## License + +Licensed under either of + +- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) +- MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) + +at your option. + +Portions of this library are derived from [curve25519-dalek] (isis lovecruft, Henry de Valence) +and [ed25519-zebra] (Zcash Foundation), both dual-licensed MIT/Apache-2.0. + +[curve25519-dalek]: https://github.com/dalek-cryptography/curve25519-dalek +[ed25519-zebra]: https://github.com/ZcashFoundation/ed25519-zebra diff --git a/README_dalek.md b/README_dalek.md new file mode 100644 index 0000000..463ebb9 --- /dev/null +++ b/README_dalek.md @@ -0,0 +1,31 @@ +

+dalek-cryptography logo: a dalek with edwards curves as sparkles coming out of its radar-schnozzley blaster thingies +

+ +# Dalek elliptic curve cryptography + +This repo contains pure-Rust crates for elliptic curve cryptography: + +| Crate | Description | Crates.io | Docs | CI | +-------------------------------------------|----------------|-----------|------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- +| [`curve25519‑dalek`](./curve25519) | A library for arithmetic over the Curve25519 and Ristretto elliptic curves and their associated scalars. | [![](https://img.shields.io/crates/v/curve25519.svg)](https://crates.io/crates/curve25519) | [![](https://img.shields.io/docsrs/curve25519)](https://docs.rs/curve25519) | [![CI](https://github.com/dalek-cryptography/curve25519/actions/workflows/curve25519.yml/badge.svg?branch=main)](https://github.com/dalek-cryptography/curve25519/actions/workflows/curve25519.yml) | +| [`ed25519‑dalek`](./ed25519-dalek) | An implementation of the EdDSA digital signature scheme over Curve25519. | [![](https://img.shields.io/crates/v/ed25519-dalek.svg)](https://crates.io/crates/ed25519-dalek) | [![](https://docs.rs/ed25519-dalek/badge.svg)](https://docs.rs/ed25519-dalek) | [![CI](https://github.com/dalek-cryptography/curve25519/actions/workflows/ed25519-dalek.yml/badge.svg?branch=main)](https://github.com/dalek-cryptography/curve25519/actions/workflows/ed25519-dalek.yml) | +| [`x25519‑dalek`](./x25519-dalek) | An implementation of elliptic curve Diffie-Hellman key exchange over Curve25519. | [![](https://img.shields.io/crates/v/x25519-dalek.svg)](https://crates.io/crates/x25519-dalek) | [![](https://docs.rs/x25519-dalek/badge.svg)](https://docs.rs/x25519-dalek) | [![CI](https://github.com/dalek-cryptography/curve25519/actions/workflows/x25519-dalek.yml/badge.svg?branch=main)](https://github.com/dalek-cryptography/curve25519/actions/workflows/x25519-dalek.yml) | + +There is also the [`curve25519-derive`](./curve25519-derive) crate, which is just a helper crate with some macros that make curve25519 easier to write. + +# Contributing + +Please see [`CONTRIBUTING.md`](./CONTRIBUTING.md). + +# Code of Conduct + +We follow the [Rust Code of Conduct](http://www.rust-lang.org/conduct.html), +with the following additional clauses: + +* We respect the rights to privacy and anonymity for contributors and people in + the community. If someone wishes to contribute under a pseudonym different to + their primary identity, that wish is to be respected by all contributors. diff --git a/curve25519-cuda/Cargo.toml b/curve25519-cuda/Cargo.toml new file mode 100644 index 0000000..86b41b2 --- /dev/null +++ b/curve25519-cuda/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "curve25519-cuda" +version = "0.1.0" +edition = "2024" + +[dependencies] diff --git a/curve25519-cuda/src/lib.rs b/curve25519-cuda/src/lib.rs new file mode 100644 index 0000000..b93cf3f --- /dev/null +++ b/curve25519-cuda/src/lib.rs @@ -0,0 +1,14 @@ +pub fn add(left: u64, right: u64) -> u64 { + left + right +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn it_works() { + let result = add(2, 2); + assert_eq!(result, 4); + } +} diff --git a/curve25519-derive/Cargo.toml b/curve25519-derive/Cargo.toml new file mode 100644 index 0000000..7d93270 --- /dev/null +++ b/curve25519-derive/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "curve25519-derive" +version = "0.1.0" +edition = "2024" + +[dependencies] diff --git a/curve25519-derive/src/lib.rs b/curve25519-derive/src/lib.rs new file mode 100644 index 0000000..b93cf3f --- /dev/null +++ b/curve25519-derive/src/lib.rs @@ -0,0 +1,14 @@ +pub fn add(left: u64, right: u64) -> u64 { + left + right +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn it_works() { + let result = add(2, 2); + assert_eq!(result, 4); + } +} diff --git a/curve25519/Cargo.toml b/curve25519/Cargo.toml new file mode 100644 index 0000000..f75a6f5 --- /dev/null +++ b/curve25519/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "curve25519" +version = "0.1.0" +edition = "2024" + +[dependencies] diff --git a/curve25519/src/lib.rs b/curve25519/src/lib.rs new file mode 100644 index 0000000..b93cf3f --- /dev/null +++ b/curve25519/src/lib.rs @@ -0,0 +1,14 @@ +pub fn add(left: u64, right: u64) -> u64 { + left + right +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn it_works() { + let result = add(2, 2); + assert_eq!(result, 4); + } +} diff --git a/ed25519-heea/Cargo.toml b/ed25519-heea/Cargo.toml new file mode 100644 index 0000000..2c8f014 --- /dev/null +++ b/ed25519-heea/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "ed25519-heea" +version = "0.1.0" +edition = "2024" + +[dependencies] diff --git a/ed25519-heea/src/lib.rs b/ed25519-heea/src/lib.rs new file mode 100644 index 0000000..b93cf3f --- /dev/null +++ b/ed25519-heea/src/lib.rs @@ -0,0 +1,14 @@ +pub fn add(left: u64, right: u64) -> u64 { + left + right +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn it_works() { + let result = add(2, 2); + assert_eq!(result, 4); + } +}