added multiscalar mult interface for p256k1

input-output-hk · Jun 8, 2021 · 8e1805a · 8e1805a
1 parent f90af13
commit 8e1805a
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diff --git a/chain-vote/src/gang/p256k1.rs b/chain-vote/src/gang/p256k1.rs
@@ -147,6 +147,18 @@ impl GroupElement {
         }
         sum
     }
+
+    pub fn vartime_multiscalar_multiplication<I, J>(scalars: I, points: J) -> Self
+        where
+            I: IntoIterator<Item = Scalar>,
+            J: IntoIterator<Item = GroupElement>,
+    {
+        let mut sum = GroupElement::zero();
+        for (scalar, point) in scalars.into_iter().zip(points.into_iter()) {
+            sum = sum + scalar * point;
+        }
+        sum
+    }
 }
 
 impl Scalar {

diff --git a/chain-vote/src/gang/ristretto255.rs b/chain-vote/src/gang/ristretto255.rs
@@ -83,6 +83,10 @@ impl GroupElement {
         }
         sum
     }
+
+    /// Variable time multiscalar multiplication. Takes as input an iterator of scalar, and an
+    /// iterator over group elements, and computes a variable time multiscalar operation. Should
+    /// only be used when the scalar are not secret.
     pub fn vartime_multiscalar_multiplication<I, J>(scalars: I, points: J) -> Self
     where
         I: IntoIterator<Item = Scalar>,