A minimal RedDSA implementation for use in Zcash.

Two parameterizations of RedJubjub are used in Zcash, one for BindingSig and one for SpendAuthSig. This library distinguishes these in the type system, using the sealed SigType trait as a type-level enum.

In addition to the Signature, SigningKey, VerificationKey types, the library also provides VerificationKeyBytes, a refinement of a [u8; 32] indicating that bytes represent an encoding of a RedJubjub verification key. This allows the VerificationKey type to cache verification checks related to the verification key encoding.

Examples

Creating a BindingSig, serializing and deserializing it, and verifying the signature:

# use std::convert::TryFrom;
use rand::thread_rng;
use reddsa::*;

let msg = b"Hello!";

// Generate a secret key and sign the message
let sk = SigningKey::<Binding>::new(thread_rng());
let sig = sk.sign(thread_rng(), msg);

// Types can be converted to raw byte arrays using From/Into
let sig_bytes: [u8; 64] = sig.into();
let pk_bytes: [u8; 32] = VerificationKey::from(&sk).into();

// Deserialize and verify the signature.
let sig: Signature<Binding> = sig_bytes.into();
assert!(
    VerificationKey::try_from(pk_bytes)
        .and_then(|pk| pk.verify(msg, &sig))
        .is_ok()
);

docs

cargo doc --features "nightly" --open