nizk/commit: rename from stage1 to commit, proper term

1 files changed, 0 insertions, 131 deletions

diff --git a/nizk/stage1/stage1.go b/nizk/stage1/stage1.go
deleted file mode 100644
index 3b97887..0000000
--- a/nizk/stage1/stage1.go
+++ /dev/null
@@ -1,131 +0,0 @@
-package stage1
-
-import (
-	"crypto/sha512"
-
-	"kesim.org/seal/curve"
-)
-
-// This is a construction of a proof of a statement of the form
-// σ ==	   [(Φ = g^(αβ))   && (A = g^α) && (Β = g^β)]
-//		|| [(Φ = g^(αβ+1)) && (A = g^α) && (Β = g^β)]
-// for given Φ, A and B
-
-type Scalar = curve.Curve25519Scalar
-type Point = curve.Curve25519Point
-
-var Curve = curve.Curve25519
-var g = Curve.Generator()
-var one = Curve.ScalarOne()
-
-type Statement struct {
-	α    *Scalar
-	β    *Scalar
-	plus bool
-	*Commitment
-}
-
-type Commitment struct {
-	Φ *Point
-	A *Point
-	B *Point
-}
-
-func NewStatement(α, β *Scalar, plus bool) *Statement {
-	return &Statement{
-		α:          α,
-		β:          β,
-		plus:       plus,
-		Commitment: commitment(α, β, plus),
-	}
-}
-
-func commitment(α, β *Scalar, plus bool) *Commitment {
-	var Φ *Point
-	φ := α.Mul(β)
-
-	if plus {
-		Φ = g.Exp(φ.Add(one))
-	} else {
-		Φ = g.Exp(φ)
-	}
-	return &Commitment{
-		Φ: Φ,
-		A: g.Exp(α),
-		B: g.Exp(β),
-	}
-}
-
-func (s *Statement) Commit() *Commitment {
-	return s.Commitment
-}
-
-type Proof struct {
-	Ch  [2]*Scalar
-	Rho [2]*Scalar
-}
-
-func (s *Statement) Proof() *Proof {
-	var ε [2][2]*Point
-	var r1, r2, ω *Scalar
-	r1 = Curve.RandomScalar()
-	r2 = Curve.RandomScalar()
-	ω = Curve.RandomScalar()
-
-	if s == nil {
-		panic("s is nil")
-	} else if ω == nil {
-		panic("ω is nil")
-	}
-
-	if s.plus {
-		ε[0][0] = g.Exp(r1)
-		ε[0][1] = s.B.Exp(r1).Mul(g.Exp(ω))
-		ε[1][0] = g.Exp(r2)
-		ε[1][1] = s.B.Exp(r2)
-	} else {
-		ε[0][0] = g.Exp(r1)
-		ε[0][1] = s.B.Exp(r1)
-		ε[1][0] = g.Exp(r2).Mul(s.A.Exp(ω))
-		ε[1][1] = s.B.Exp(r2).Mul(s.Φ.Div(g).Exp(ω))
-	}
-
-	ch := challenge(g, s.Φ, s.A, s.B, ε[0][0], ε[0][1], ε[1][0], ε[1][1])
-	pr := &Proof{}
-
-	if s.plus {
-		pr.Ch[0] = ω
-		pr.Ch[1] = ch.Sub(ω)
-		pr.Rho[0] = r1.Sub(s.α.Mul(pr.Ch[0]))
-		pr.Rho[1] = r2.Sub(s.α.Mul(pr.Ch[1]))
-	} else {
-		pr.Ch[0] = ch.Sub(ω)
-		pr.Ch[1] = ω
-		pr.Rho[0] = r1.Sub(s.α.Mul(pr.Ch[0]))
-		pr.Rho[1] = r2
-	}
-
-	return pr
-}
-
-func challenge(points ...*Point) *Scalar {
-	h512 := sha512.New()
-	for _, p := range points {
-		h512.Write(p.Bytes())
-	}
-	ch, e := Curve.ScalarFromBytes(h512.Sum(nil))
-	if e != nil {
-		panic(e)
-	}
-	return ch
-}
-
-func (c *Commitment) Verify(p *Proof) bool {
-	var ε [2][2]*Point
-	ε[0][0] = g.Exp(p.Rho[0]).Mul(c.A.Exp(p.Ch[0]))
-	ε[0][1] = c.B.Exp(p.Rho[0]).Mul(c.Φ.Exp(p.Ch[0]))
-	ε[1][0] = g.Exp(p.Rho[1]).Mul(c.A.Exp(p.Ch[1]))
-	ε[1][1] = c.B.Exp(p.Rho[1]).Mul(c.Φ.Div(g).Exp(p.Ch[1]))
-	ch := challenge(g, c.Φ, c.A, c.B, ε[0][0], ε[0][1], ε[1][0], ε[1][1])
-	return p.Ch[0].Add(p.Ch[1]).Equal(ch)
-}