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-rw-r--r--nizk/commit.go40
-rw-r--r--nizk/stage1.go82
-rw-r--r--nizk/stage1_test.go16
-rw-r--r--nizk/stage2.go51
-rw-r--r--nizk/stage2_test.go13
5 files changed, 104 insertions, 98 deletions
diff --git a/nizk/commit.go b/nizk/commit.go
index 957e4a9..5634b16 100644
--- a/nizk/commit.go
+++ b/nizk/commit.go
@@ -7,18 +7,20 @@ import (
type Bit struct {
id Bytes
- bit bool
+ set bool
α *Scalar
β *Scalar
- com *Commitment
+ *Commitment
prf *Proof
+
+ *Stage
}
type Commitment struct {
A *Point // g^α
B *Point // g^β
- C *Point // g^(ab)g^(bit)
+ C *Point // g^(ab)g^(set)
}
// This is a construction of a proof of a statement of the form
@@ -36,51 +38,43 @@ type Proof struct {
}
}
-func NewBit(id Bytes, bit bool) *Bit {
+func NewBit(id Bytes, set bool) *Bit {
α, β := Curve.RandomScalar(), Curve.RandomScalar()
- return NewBitFromScalars(id, bit, α, β)
+ return NewBitFromScalars(id, set, α, β)
}
-func NewBitFromScalars(id Bytes, bit bool, α, β *Scalar) *Bit {
+func NewBitFromScalars(id Bytes, set bool, α, β *Scalar) *Bit {
return &Bit{
id: id,
- bit: bit,
+ set: set,
α: α,
β: β,
}
}
func (b *Bit) IsSet() bool {
- return b.bit
-}
-
-func (b *Bit) Id() Bytes {
- return b.id
-}
-
-func (b *Bit) Scalars() (α *Scalar, β *Scalar) {
- return b.α, b.β
+ return b.set
}
func (b *Bit) commit() *Commitment {
- if b.com != nil {
- return b.com
+ if b.Commitment != nil {
+ return b.Commitment
}
var C *Point
c := b.α.Mul(b.β)
- if b.bit {
+ if b.set {
C = G.Exp(c.Add(One))
} else {
C = G.Exp(c)
}
- b.com = &Commitment{
+ b.Commitment = &Commitment{
C: C,
A: G.Exp(b.α),
B: G.Exp(b.β),
}
- return b.com
+ return b.Commitment
}
func (s *Bit) proof() *Proof {
@@ -95,7 +89,7 @@ func (s *Bit) proof() *Proof {
w = Curve.RandomScalar()
c := s.commit()
- if s.bit {
+ if s.set {
e[0][0] = G.Exp(r1)
e[0][1] = c.B.Exp(r1).Mul(G.Exp(w))
e[1][0] = G.Exp(r2)
@@ -110,7 +104,7 @@ func (s *Bit) proof() *Proof {
ch := Challenge(G, c.C, c.A, c.B, e[0][0], e[0][1], e[1][0], e[1][1], s.id)
pr := &Proof{}
- if s.bit {
+ if s.set {
pr.C.Ch[0] = w
pr.C.Ch[1] = ch.Sub(w)
pr.C.R[0] = r1.Sub(s.α.Mul(pr.C.Ch[0]))
diff --git a/nizk/stage1.go b/nizk/stage1.go
index 4cd9547..3ebed27 100644
--- a/nizk/stage1.go
+++ b/nizk/stage1.go
@@ -1,15 +1,17 @@
package nizk
-import . "kesim.org/seal/common"
+import (
+ "fmt"
-type Stage struct {
- bit *Bit
+ . "kesim.org/seal/common"
+)
+type Stage struct {
x *Scalar
r *Scalar
- com *StageCommitment
- rev *StageReveal
+ *StageCommitment
+ *StageReveal
}
type StageCommitment struct {
@@ -33,39 +35,43 @@ type Stage1Proof struct {
Rho [2][2]*Scalar
}
-func (b *Bit) stage(x, r *Scalar) *Stage {
+func (b *Bit) stage(x, r *Scalar) {
b.Commit() // ensure non-null values for A, B, C
- return &Stage{
- x: x,
- r: r,
- bit: b,
+ b.Stage = &Stage{
+ x: x,
+ r: r,
}
}
func (s *Stage) commit(Xs ...*Point) *StageCommitment {
- if s.com != nil {
- return s.com
+ if s.StageCommitment != nil {
+ return s.StageCommitment
}
- s.com = &StageCommitment{
+ s.StageCommitment = &StageCommitment{
X: G.Exp(s.x),
R: G.Exp(s.r),
}
- return s.com
+ return s.StageCommitment
}
-func (b *Bit) Stage(Xs ...*Point) (c *Stage, s *StageCommitment) {
+func (b *Bit) StageCommit(Xs ...*Point) (s *StageCommitment) {
x := Curve.RandomScalar()
r := Curve.RandomScalar()
return b.StageFromScalars(x, r, Xs...)
}
-func (b *Bit) StageFromScalars(x, r *Scalar, Xs ...*Point) (s *Stage, c *StageCommitment) {
- s = b.stage(x, r)
- return s, s.commit(Xs...)
+func (b *Bit) StageFromScalars(x, r *Scalar, Xs ...*Point) (c *StageCommitment) {
+ b.stage(x, r)
+ return b.Stage.commit(Xs...)
}
-func (s *Stage) reveal(prev_true bool, Xs ...*Point) (r *StageReveal, e error) {
+func (b *Bit) reveal(prev_true bool, Xs ...*Point) (r *StageReveal, e error) {
+ s := b.Stage
+ if s == nil {
+ return nil, fmt.Errorf("stage not ready")
+ }
+
// TODO: Calculate Y based on the Xs and our own X_i
// as Π_(i<k) X_k / Π_(i>k) X_k
// For now:
@@ -73,8 +79,8 @@ func (s *Stage) reveal(prev_true bool, Xs ...*Point) (r *StageReveal, e error) {
r = &StageReveal{Y: Y}
- if prev_true && s.bit.IsSet() {
- r.Z = s.com.R.Exp(s.x)
+ if prev_true && b.IsSet() {
+ r.Z = s.R.Exp(s.x)
} else {
r.Z = Y.Exp(s.x)
}
@@ -82,41 +88,44 @@ func (s *Stage) reveal(prev_true bool, Xs ...*Point) (r *StageReveal, e error) {
return r, e
}
-func (s *Stage) RevealStage1(Xs ...*Point) (rev *StageReveal, pr *Stage1Proof, e error) {
+func (b *Bit) RevealStage1(Xs ...*Point) (rev *StageReveal, pr *Stage1Proof, e error) {
+ s := b.Stage
+ if s == nil {
+ return nil, nil, fmt.Errorf("stage not ready")
+ }
var ε [2][4]*Point
var r1, r2, ρ1, ρ2, ω *Scalar
for _, s := range []**Scalar{&r1, &r2, &ρ1, &ρ2, &ω} {
*s = Curve.RandomScalar()
}
c := s.commit()
- bc := s.bit.com
- rev, e = s.reveal(true, Xs...)
+ rev, e = b.reveal(true, Xs...)
if e != nil {
return nil, nil, e
}
- if s.bit.IsSet() {
+ if b.IsSet() {
ε[0][0] = G.Exp(r1).Mul(c.X.Exp(ω))
- ε[0][1] = G.Exp(r2).Mul(bc.A.Exp(ω))
+ ε[0][1] = G.Exp(r2).Mul(b.A.Exp(ω))
ε[0][2] = rev.Y.Exp(r1).Mul(rev.Z.Exp(ω))
- ε[0][3] = bc.B.Exp(r2).Mul(bc.C.Exp(ω))
+ ε[0][3] = b.B.Exp(r2).Mul(b.C.Exp(ω))
ε[1][0] = G.Exp(ρ1)
ε[1][1] = G.Exp(ρ2)
ε[1][2] = c.R.Exp(ρ1)
- ε[1][3] = bc.B.Exp(ρ2)
+ ε[1][3] = b.B.Exp(ρ2)
} else {
ε[0][0] = G.Exp(r1)
ε[0][1] = G.Exp(r2)
ε[0][2] = rev.Y.Exp(r1)
- ε[0][3] = bc.B.Exp(r2)
+ ε[0][3] = b.B.Exp(r2)
ε[1][0] = G.Exp(ρ1).Mul(c.X.Exp(ω))
- ε[1][1] = G.Exp(ρ2).Mul(bc.A.Exp(ω))
+ ε[1][1] = G.Exp(ρ2).Mul(b.A.Exp(ω))
ε[1][2] = c.R.Exp(ρ1).Mul(rev.Z.Exp(ω))
- ε[1][3] = bc.B.Exp(ρ2).Mul(bc.C.Div(G).Exp(ω))
+ ε[1][3] = b.B.Exp(ρ2).Mul(b.C.Div(G).Exp(ω))
}
- p := []Bytes{G, bc.A, bc.B, bc.C, c.R, c.X, rev.Y, rev.Z}
+ p := []Bytes{G, b.A, b.B, b.C, c.R, c.X, rev.Y, rev.Z}
for _, e := range ε[0] {
p = append(p, e)
}
@@ -126,25 +135,24 @@ func (s *Stage) RevealStage1(Xs ...*Point) (rev *StageReveal, pr *Stage1Proof, e
ch := Challenge(p...)
pr = &Stage1Proof{}
- α, _ := s.bit.Scalars()
- if s.bit.IsSet() {
+ if b.IsSet() {
pr.Ch[0] = ω
pr.Ch[1] = ch.Sub(ω)
pr.Rho[0][0] = r1
pr.Rho[0][1] = r2
pr.Rho[1][0] = ρ1.Sub(s.x.Mul(pr.Ch[1]))
- pr.Rho[1][1] = ρ2.Sub(α.Mul(pr.Ch[1]))
+ pr.Rho[1][1] = ρ2.Sub(b.α.Mul(pr.Ch[1]))
} else {
pr.Ch[0] = ch.Sub(ω)
pr.Ch[1] = ω
pr.Rho[0][0] = r1.Sub(s.x.Mul(pr.Ch[0]))
- pr.Rho[0][1] = r2.Sub(α.Mul(pr.Ch[0]))
+ pr.Rho[0][1] = r2.Sub(b.α.Mul(pr.Ch[0]))
pr.Rho[1][0] = ρ1
pr.Rho[1][1] = ρ2
}
- s.rev = rev
+ s.StageReveal = rev
return rev, pr, e
}
diff --git a/nizk/stage1_test.go b/nizk/stage1_test.go
index 9c6d957..954f356 100644
--- a/nizk/stage1_test.go
+++ b/nizk/stage1_test.go
@@ -13,10 +13,10 @@ func TestStage1Simple(t *testing.T) {
bc1, _ := b1.Commit()
bc2, _ := b2.Commit()
- s1, c1 := b1.Stage()
- s2, c2 := b2.Stage()
- r1, pr1, _ := s1.RevealStage1() // Note: no Xs.
- r2, pr2, _ := s2.RevealStage1() // Note: no Xs.
+ c1 := b1.StageCommit()
+ c2 := b2.StageCommit()
+ r1, pr1, _ := b1.RevealStage1() // Note: no Xs.
+ r2, pr2, _ := b2.RevealStage1() // Note: no Xs.
if !bc1.VerifyStage1(c1, r1, pr1) {
t.Fatal("Could not verify st1 with c1 and pr1, plus=true case")
}
@@ -40,10 +40,10 @@ func TestStage1FromScalars(t *testing.T) {
bc1, _ := b1.Commit()
bc2, _ := b2.Commit()
- s1, c1 := b1.StageFromScalars(r, x)
- s2, c2 := b2.StageFromScalars(x, r)
- r1, pr1, _ := s1.RevealStage1() // Note: no Xs
- r2, pr2, _ := s2.RevealStage1() // Note: no Xs
+ c1 := b1.StageFromScalars(r, x)
+ c2 := b2.StageFromScalars(x, r)
+ r1, pr1, _ := b1.RevealStage1() // Note: no Xs
+ r2, pr2, _ := b2.RevealStage1() // Note: no Xs
if !bc1.VerifyStage1(c1, r1, pr1) {
t.Fatal("Could not verify st1 with c1 and pr1, plus=true case")
}
diff --git a/nizk/stage2.go b/nizk/stage2.go
index 37cd8c1..e6e6b34 100644
--- a/nizk/stage2.go
+++ b/nizk/stage2.go
@@ -1,6 +1,8 @@
package nizk
import (
+ "fmt"
+
. "kesim.org/seal/common"
)
@@ -19,7 +21,11 @@ type Stage2Proof struct {
R3 [2]*Scalar
}
-func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *StageReveal, pr *Stage2Proof, e error) {
+func (b *Bit) RevealStage2(prev *Bit, Xs ...*Point) (rv2 *StageReveal, pr *Stage2Proof, e error) {
+ s := b.Stage
+ if s == nil {
+ return nil, nil, fmt.Errorf("stage not ready")
+ }
var (
ε1, ε1_ [3]Bytes
ε2, ε2_ [3]Bytes
@@ -36,31 +42,30 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
}
}
- bc := s.bit.com
- c1 := prev.com
- c2 := s.com
- rv1 := prev.rev
- rv2, e = s.reveal(prev_true, Xs...)
+ c1 := prev.StageCommitment
+ c2 := s.StageCommitment
+ rv1 := prev.StageReveal
+ rv2, e = b.reveal(prev.IsSet(), Xs...)
if e != nil {
return nil, nil, e
}
- if !prev_true {
+ if !prev.IsSet() {
ε1[0] = G.Exp(ρ1[0]).Mul(c2.X.Exp(ω[0]))
ε1[1] = G.Exp(ρ1[1]).Mul(c1.X.Exp(ω[0]))
- ε1[2] = G.Exp(ρ1[2]).Mul(bc.A.Exp(ω[0]))
+ ε1[2] = G.Exp(ρ1[2]).Mul(b.A.Exp(ω[0]))
ε1_[0] = c2.R.Exp(ρ1[0]).Mul(rv2.Z.Exp(ω[0]))
ε1_[1] = c1.R.Exp(ρ1[1]).Mul(rv1.Z.Exp(ω[0]))
- ε1_[2] = bc.B.Exp(ρ1[2]).Mul(bc.C.Div(G).Exp(ω[0]))
+ ε1_[2] = b.B.Exp(ρ1[2]).Mul(b.C.Div(G).Exp(ω[0]))
ε2[0] = G.Exp(ρ2[0]).Mul(c2.X.Exp(ω[1]))
ε2[1] = G.Exp(ρ2[1]).Mul(c1.X.Exp(ω[1]))
- ε2[2] = G.Exp(ρ2[2]).Mul(bc.A.Exp(ω[1]))
+ ε2[2] = G.Exp(ρ2[2]).Mul(b.A.Exp(ω[1]))
ε2_[0] = rv2.Y.Exp(ρ2[0]).Mul(rv2.Z.Exp(ω[1]))
ε2_[1] = c1.R.Exp(ρ2[1]).Mul(rv1.Z.Exp(ω[1]))
- ε2_[2] = bc.B.Exp(ρ2[2]).Mul(bc.C.Exp(ω[1]))
+ ε2_[2] = b.B.Exp(ρ2[2]).Mul(b.C.Exp(ω[1]))
ε3[0] = G.Exp(ρ3[0])
ε3[1] = G.Exp(ρ3[1])
@@ -68,22 +73,22 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
ε3_[0] = rv2.Y.Exp(ρ3[0])
ε3_[1] = rv1.Y.Exp(ρ3[1])
} else {
- if s.bit.IsSet() {
+ if b.IsSet() {
ε1[0] = G.Exp(ρ1[0])
ε1[1] = G.Exp(ρ1[1])
ε1[2] = G.Exp(ρ1[2])
ε1_[0] = c2.R.Exp(ρ1[0])
ε1_[1] = c1.R.Exp(ρ1[1])
- ε1_[2] = bc.B.Exp(ρ1[2])
+ ε1_[2] = b.B.Exp(ρ1[2])
ε2[0] = G.Exp(ρ2[0]).Mul(c2.X.Exp(ω[0]))
ε2[1] = G.Exp(ρ2[1]).Mul(c1.X.Exp(ω[0]))
- ε2[2] = G.Exp(ρ2[2]).Mul(bc.A.Exp(ω[0]))
+ ε2[2] = G.Exp(ρ2[2]).Mul(b.A.Exp(ω[0]))
ε2_[0] = rv2.Y.Exp(ρ2[0]).Mul(rv2.Z.Exp(ω[0]))
ε2_[1] = c1.R.Exp(ρ2[1]).Mul(rv1.Z.Exp(ω[0]))
- ε2_[2] = bc.B.Exp(ρ2[2]).Mul(bc.C.Exp(ω[0]))
+ ε2_[2] = b.B.Exp(ρ2[2]).Mul(b.C.Exp(ω[0]))
ε3[0] = G.Exp(ρ3[0]).Mul(c2.X.Exp(ω[1]))
ε3[1] = G.Exp(ρ3[1]).Mul(c1.X.Exp(ω[1]))
@@ -93,11 +98,11 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
} else {
ε1[0] = G.Exp(ρ1[0]).Mul(c2.X.Exp(ω[0]))
ε1[1] = G.Exp(ρ1[1]).Mul(c1.X.Exp(ω[0]))
- ε1[2] = G.Exp(ρ1[2]).Mul(bc.A.Exp(ω[0]))
+ ε1[2] = G.Exp(ρ1[2]).Mul(b.A.Exp(ω[0]))
ε1_[0] = c2.R.Exp(ρ1[0]).Mul(rv2.Z.Exp(ω[0]))
ε1_[1] = c1.R.Exp(ρ1[1]).Mul(rv1.Z.Exp(ω[0]))
- ε1_[2] = bc.B.Exp(ρ1[2]).Mul(bc.C.Div(G).Exp(ω[0]))
+ ε1_[2] = b.B.Exp(ρ1[2]).Mul(b.C.Div(G).Exp(ω[0]))
ε2[0] = G.Exp(ρ2[0])
ε2[1] = G.Exp(ρ2[1])
@@ -105,7 +110,7 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
ε2_[0] = rv2.Y.Exp(ρ2[0])
ε2_[1] = c1.R.Exp(ρ2[1])
- ε2_[2] = bc.B.Exp(ρ2[2])
+ ε2_[2] = b.B.Exp(ρ2[2])
ε3[0] = G.Exp(ρ3[0]).Mul(c2.X.Exp(ω[1]))
ε3[1] = G.Exp(ρ3[1]).Mul(c1.X.Exp(ω[1]))
@@ -115,7 +120,7 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
}
}
- points := []Bytes{G, bc.A, bc.B, bc.C, c2.R, c2.X, rv2.Y, rv2.Z, c1.R, c1.X, rv1.Y, rv1.Z}
+ points := []Bytes{G, b.A, b.B, b.C, c2.R, c2.X, rv2.Y, rv2.Z, c1.R, c1.X, rv1.Y, rv1.Z}
points = append(points, ε1[:]...)
points = append(points, ε2[:]...)
points = append(points, ε3[:]...)
@@ -126,7 +131,7 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
ch := Challenge(points...)
pr = &Stage2Proof{}
- if !prev_true {
+ if !prev.IsSet() {
pr.Ch[0] = ω[0]
pr.Ch[1] = ω[1]
pr.Ch[2] = ch.Sub(ω[0]).Sub(ω[1])
@@ -142,14 +147,14 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
pr.R3[0] = ρ3[0].Sub(s.x.Mul(pr.Ch[2]))
pr.R3[1] = ρ3[1].Sub(prev.x.Mul(pr.Ch[2]))
} else {
- if s.bit.IsSet() {
+ if b.IsSet() {
pr.Ch[0] = ch.Sub(ω[0]).Sub(ω[1])
pr.Ch[1] = ω[0]
pr.Ch[2] = ω[1]
pr.R1[0] = ρ1[0].Sub(s.x.Mul(pr.Ch[0]))
pr.R1[1] = ρ1[1].Sub(prev.x.Mul(pr.Ch[0]))
- pr.R1[2] = ρ1[2].Sub(s.bit.α.Mul(pr.Ch[0]))
+ pr.R1[2] = ρ1[2].Sub(b.α.Mul(pr.Ch[0]))
pr.R2[0] = ρ2[0]
pr.R2[1] = ρ2[1]
@@ -168,7 +173,7 @@ func (s *Stage) RevealStage2(prev_true bool, prev *Stage, Xs ...*Point) (rv2 *St
pr.R2[0] = ρ2[0].Sub(s.x.Mul(pr.Ch[1]))
pr.R2[1] = ρ2[1].Sub(prev.x.Mul(pr.Ch[1]))
- pr.R2[2] = ρ2[2].Sub(s.bit.α.Mul(pr.Ch[1]))
+ pr.R2[2] = ρ2[2].Sub(b.α.Mul(pr.Ch[1]))
pr.R3[0] = ρ3[0]
pr.R3[1] = ρ3[1]
diff --git a/nizk/stage2_test.go b/nizk/stage2_test.go
index c0a5656..e5b44c6 100644
--- a/nizk/stage2_test.go
+++ b/nizk/stage2_test.go
@@ -8,16 +8,15 @@ import (
func TestStage2Simple(t *testing.T) {
id1 := Curve.RandomScalar()
- id2 := Curve.RandomScalar()
- b1 := NewBit(id1, true)
- b2 := NewBit(id2, false)
+ b1 := NewBit(id1, false)
+ b2 := NewBit(id1, true)
- s1, c1 := b1.Stage()
- r1, _, _ := s1.RevealStage1()
+ c1 := b1.StageCommit()
+ r1, _, _ := b1.RevealStage1()
bc2, _ := b2.Commit()
- s2, c2 := b2.Stage()
- r2, p2, e := s2.RevealStage2(true, s1)
+ c2 := b2.StageCommit()
+ r2, p2, e := b2.RevealStage2(b1)
if e != nil {
t.Fatalf("e: %v", e)
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-09-11 09:42:44 +0000