Crate decaf377_rdsa

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decaf377-rdsa is a variant of RedDSA, instantiated using the decaf377 group.

Signatures are parameterized by domain (for instance, Binding and SpendAuth); this library distinguishes different domains in the type system using the 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.


This code is a work-in-progress, and the entire specification is still subject to change. In particular, it’s likely that the basepoint used for binding signatures will change in the future as the decaf377 spec evolves.


Creating a spend authorization signature, serializing and deserializing it, and verifying the signature:

use rand::thread_rng;
use decaf377_rdsa::*;

let msg = b"Hello!";

// Generate a secret key and sign the message
let sk = SigningKey::<SpendAuth>::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<SpendAuth> = sig_bytes.into();
        .and_then(|pk| pk.verify(msg, &sig))


This library is based on the redjubjub crate.


  • Performs batch decaf377-rdsa signature verification.



  • A type variable corresponding to Zcash’s BindingSig.
  • An error related to decaf377-rdsa signatures.
  • A type variable corresponding to Zcash’s SpendAuthSig.


  • Abstracts over different signature domains.

Type Aliases§