# dalek-cryptography/curve25519-dalek

A pure-Rust implementation of group operations on Ristretto and Curve25519

Repository: https://github.com/dalek-cryptography/curve25519-dalek
Canonical: https://ross.abutalabs.com/products/curve25519-dalek
Language: Rust
License: NOASSERTION
License Family: other
Topics: cryptography, elliptic-curves, curve25519, ristretto, montgomery, edwards-curve
Last push: 2026-08-29T17:55:01+00:00

## Health v2 (maintenance only)
Score: 68/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 8, longevity 100
- inputs: {"age_days": 3555, "days_push": 4, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1188, forks 596 (observed 2026-09-01T02:14:00.679473+00:00)

## What it is
A pure-Rust library providing group operations on the Curve25519 and ristretto255 elliptic curves, along with related crates for Ed25519 signatures and X25519 key exchange. It is widely used, with over 240 million downloads on crates.io.

## Use cases
- perform elliptic curve scalar multiplication in Rust
- implement Ed25519 digital signatures
- do X25519 Diffie-Hellman key exchange
- use ristretto255 group arithmetic for protocols
- build cryptographic protocols needing Curve25519 primitives

## When to choose
- you need audited, pure-Rust Curve25519 arithmetic
- you want Ed25519 or X25519 in a Rust project
- you need ristretto255 group operations
- you want no_std or embedded-friendly crypto primitives

## When to avoid
- you need higher-level APIs like TLS or full protocol stacks
- you need curves other than Curve25519/Ristretto
- you need a non-Rust language binding

## Facets
- artifact type: library
- maturity: stable
- function: cryptography
- domain: security
- platform: rust, cross-platform
- tags: elliptic-curves, curve25519, ristretto, ed25519, x25519, pure-rust, no-std, cryptography

## Member repositories
- dalek-cryptography/curve25519-dalek (main) score 68

## Provenance
- Observed fields: from GitHub, fetched 2026-09-01T02:14:00.679473+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:23:36.367334+00:00, confidence not recorded.
  - readme: https://github.com/dalek-cryptography/curve25519-dalek (fetched 2026-09-01T02:14:00.679473+00:00, sha 4b704a385a2c)
  - registry_crates: https://crates.io/api/v1/crates/curve25519-dalek (fetched 2026-08-29T12:30:31.973034+00:00, sha 52cd3e102475)
- Data as of 2026-08-30T08:39:29.467469+00:00.