nizk/stage1: NIZK proofs for commit phase

Implemented the NIZK for the B.a) Commit on page 4

2 files changed, 10 insertions, 0 deletions

diff --git a/curve/curve.go b/curve/curve.go
index 36c9eed..5b41352 100644
--- a/curve/curve.go
+++ b/curve/curve.go
@@ -24,6 +24,7 @@ type ScalarReader[S any] interface {
 	RandomScalar() S
 	ScalarFromReader(io.Reader) (S, error)
 	ScalarFromBytes([]byte) (S, error)
+	ScalarOne() S
 }
 
 type SomeCurve[S SomeScalar[s], s Data, P SomePoint[S, s, p], p Data] interface {
diff --git a/curve/ed25519.go b/curve/ed25519.go
index 3d0ba81..318c149 100644
--- a/curve/ed25519.go
+++ b/curve/ed25519.go
@@ -73,6 +73,15 @@ func (c *c25519) ScalarFromBytes(b []byte) (*scalar, error) {
 	return (*scalar)(s), e
 }
 
+func (c *c25519) ScalarOne() *scalar {
+	b := [64]byte{1}
+	one, e := c.ScalarFromBytes(b[:])
+	if e != nil {
+		panic(e)
+	}
+	return one
+}
+
 func (c *c25519) Exp(s *scalar) *point {
 	p := new(ed.Point).ScalarBaseMult((*ed.Scalar)(s))
 	return (*point)(p)