ecies-ed25519

ECIES on Twisted Edwards Curve25519 using AES-GCM and HKDF-SHA256.

ECIES can be used to encrypt data using a public key such that it can only be decrypted by the holder of the corresponding private key.

This project has not undergone a security audit. A 1.0 release will not happen until it does.

Backends

It uses the excellent curve25519-dalek library for ECC operations, and provides two different backends for HKDF-SHA256 / AES-GCM operation operations.

1. The pure_rust backend (default). It uses a collection of pure-rust implementations of SHA2, HKDF, AES, and AEAD.

2. The ring backend uses ring. It uses rock solid primitives based on BoringSSL, but cannot run on all platforms. For example it won't work on WASM. To activate this backend add this to your Cargo.toml file:

   ecies-ed25519 = { version = "0.3", features = ["ring"] }

Example Usage

let mut csprng = rand::thread_rng();
let (secret, public) = ecies_ed25519::generate_keypair(&mut csprng);

let message = "I 💖🔒";

// Encrypt the message with the public key such that only the holder of the secret key can decrypt.
let encrypted = ecies_ed25519::encrypt(&public, message.as_bytes(), &mut csprng).unwrap();

// Decrypt the message with the secret key
let decrypted = ecies_ed25519::decrypt(&secret, &encrypted);

serde Support

The serde feature is provided for serializing / deserializing private and public keys.

Running Tests

You should run tests on both backends:

cargo test --no-default-features --features "ring serde"
cargo test --no-default-features --features "pure_rust serde"

Performance

If using the pure_rust backend, by default this crate's dependencies will use software implementations of both AES and the POLYVAL universal hash function.

When targeting modern x86/x86_64 CPUs, use the following RUSTFLAGS to take advantage of high performance AES-NI and CLMUL CPU intrinsics:

RUSTFLAGS="-Ctarget-cpu=sandybridge -Ctarget-feature=+aes,+sse2,+sse4.1,+ssse3"

Future Plans

• I will be making this crate generic over both the AEAD and HKDF implementation once const-generics is resolved.

• Add support for AVX2 and AVX512

Security Audits

This project has not undergone a security audit. A 1.0 release will not happen until it does. Please contact me if you would like to fund or perform a security audit.

While this library has not undergone a security audit, some of its dependencies have. Dependency audits:

• curve25519-dalek

• ring

• aes-gcm