66 lines
2.1 KiB
Markdown
66 lines
2.1 KiB
Markdown
A minimal [RedDSA][reddsa] implementation for use in Zcash.
|
|
|
|
Two specializations of RedDSA are used in Zcash: RedJubjub and
|
|
RedPallas. For each of these, two parameterizations are used, 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 RedDSA
|
|
verification key. This allows the `VerificationKey` type to cache
|
|
verification checks related to the verification key encoding.
|
|
For all specializations of RedDSA used in Zcash, encodings of signing
|
|
and verification keys are 32 bytes.
|
|
|
|
## Examples
|
|
|
|
Creating a `BindingSig`, serializing and deserializing it, and
|
|
verifying the signature:
|
|
|
|
```rust
|
|
# 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::<sapling::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<sapling::Binding> = sig_bytes.into();
|
|
assert!(
|
|
VerificationKey::try_from(pk_bytes)
|
|
.and_then(|pk| pk.verify(msg, &sig))
|
|
.is_ok()
|
|
);
|
|
```
|
|
|
|
## FROST
|
|
|
|
You can enable ZIP-312 re-randomized FROST support with the `frost` feature.
|
|
This is still experimental since ZIP-312 is still a draft.
|
|
|
|
## docs
|
|
|
|
```shell,no_run
|
|
cargo doc --features "nightly" --open
|
|
```
|
|
|
|
## Developers guide
|
|
|
|
See [DEVELOPERS.md](DEVELOPERS.md).
|
|
|
|
|
|
[reddsa]: https://zips.z.cash/protocol/protocol.pdf#concretereddsa
|
|
[zebra]: https://github.com/ZcashFoundation/zebra
|
|
[refinement]: https://en.wikipedia.org/wiki/Refinement_type
|
|
[sealed]: https://rust-lang.github.io/api-guidelines/future-proofing.html#sealed-traits-protect-against-downstream-implementations-c-sealed
|