zecfoundation
/
frost
mirror of https://github.com/ZcashFoundation/frost.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

First stab at multiscalar speedup for computing group commitments (#345) 

* First stab at vartime multiscalar speedup for computing group commitments

* Update frost-core/src/frost.rs

---------

Co-authored-by: Conrado Gouvea <conradoplg@gmail.com>
This commit is contained in:
Deirdre Connolly 2023-05-16 20:06:22 -04:00 committed by GitHub
parent 53a30278b9
commit 07aea68b03
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 21 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
frost-core/src/frost.rs
View File

@ -24,7 +24,9 @@ pub mod keys;
pub mod round1;
pub mod round2;
use crate::{Ciphersuite, Element, Error, Field, Group, Scalar, Signature};
use crate::{
scalar_mul::VartimeMultiscalarMul, Ciphersuite, Element, Error, Field, Group, Scalar, Signature,
};
pub use self::identifier::Identifier;
@ -301,6 +303,13 @@ where
let mut group_commitment = <C::Group as Group>::identity();
// Number of signing participants we are iterating over.
let n = signing_package.signing_commitments().len();
let mut binding_scalars = Vec::with_capacity(n);
let mut binding_elements = Vec::with_capacity(n);
// Ala the sorting of B, just always sort by identifier in ascending order
//
// https://github.com/cfrg/draft-irtf-cfrg-frost/blob/master/draft-irtf-cfrg-frost.md#encoding-operations-dep-encoding
@ -313,10 +322,19 @@ where
let binding_factor = binding_factor_list[commitment.identifier].clone();
group_commitment =
group_commitment + (commitment.hiding.0 + (commitment.binding.0 * binding_factor.0));
// Collect the binding commitments and their binding factors for one big
// multiscalar multiplication at the end.
binding_elements.push(commitment.binding.0);
binding_scalars.push(binding_factor.0);
group_commitment = group_commitment + commitment.hiding.0;
}
let accumulated_binding_commitment: Element<C> =
VartimeMultiscalarMul::<C>::vartime_multiscalar_mul(binding_scalars, binding_elements);
group_commitment = group_commitment + accumulated_binding_commitment;
Ok(GroupCommitment(group_commitment))
}