Dalek elliptic curve cryptography

This repo contains pure-Rust crates for elliptic curve cryptography:

Crate	Description	Crates.io	Docs	CI
curve25519‑dalek	A library for arithmetic over the Curve25519 and Ristretto elliptic curves and their associated scalars.
ed25519‑dalek	An implementation of the EdDSA digital signature scheme over Curve25519.
x25519‑dalek	An implementation of elliptic curve Diffie-Hellman key exchange over Curve25519.

There is also the curve25519-dalek-derive crate, which is just a helper crate with some macros that make curve25519-dalek easier to write.

Contributing

Please see CONTRIBUTING.md.

Code of Conduct

We follow the Rust Code of Conduct, 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.

Beneficial AI Foundation note

This repo is based on the signal-curve25519-4.1.3 tag of https://github.com/signalapp/curve25519-dalek, with these changes:

• removed all crates besides curve25519-dalek
• removed all backends except for serial/u64
• commented out unit tests
• removed most CI workflows

Setup

1. Install Rust: https://rust-lang.org/learn/get-started/
2. Download and unzip a verus binary from https://github.com/verus-lang/verus/releases/tag/release%2F0.2025.11.23.41c5885. It's important to use exactly this version
3. The unzipped verus folder will contains a file called verus and a file called cargo-verus. Run these commands:

cd ~/.cargo/bin
ln -s /path/to/cargo-verus
ln -s /path/to/verus

4. If you're on a Mac, the first time you run cargo verus verify inside dalek-lite, you may be prompted to approve the unknown applications: cargo-verus, verus, and z3. See https://support.apple.com/en-gb/guide/mac-help/mh40616/mac.
5. Success looks like:

cd dalek-lite
cargo verus verify
... (many warnings)
verification results:: 313 verified, 0 errors
warning: `curve25519-dalek` (lib) generated 43 warnings (19 duplicates)
    Finished `dev` profile [optimized + debuginfo] target(s) in 8.99s

How to install verusfmt

cargo install --git https://github.com/Beneficial-AI-Foundation/verusfmt --rev 025d10eeb5a98052dcb7f262e5d0102d23996809

This is a version of verusfmt patched to support more Rust syntax.

See https://github.com/verus-lang/verusfmt?tab=readme-ov-file#installing-and-using-verusfmt for usage. In particular, if you want to format all Rust files, run

find . -name "*.rs" -type f | xargs -P 0 -n 1 verusfmt

Using bacon

bacon verus will show the live verification status as you make edits and save files, and it will put error messages at the top.

Install bacon from https://github.com/Canop/bacon