Switching to a different ristretto implementation

primitives/bulletproofs/inner_product.go

@@ -4,7 +4,7 @@ import (
 	"cwtch.im/tapir/primitives/core"
 	"encoding/json"
 	"git.openprivacy.ca/openprivacy/libricochet-go/log"
-	"github.com/bwesterb/go-ristretto"
+	ristretto "github.com/gtank/ristretto255"
 	"strconv"
 )
 
@@ -12,12 +12,12 @@ import (
 type InnerProductProof struct {
 	L core.PointVector
 	R core.PointVector
-	A core.Scalar
+	A *ristretto.Scalar
-	B core.Scalar
+	B *ristretto.Scalar
 }
 
 // ProveInnerProduct generates a proof for <a,b>, the inner product of a and b
-func ProveInnerProduct(a, b core.ScalarVector, u core.Point, P *ristretto.Point, G, H core.GeneratorVector, transcript *core.Transcript) InnerProductProof {
+func ProveInnerProduct(a, b core.ScalarVector, u *ristretto.Element, P *ristretto.Element, G, H core.GeneratorVector, transcript *core.Transcript) InnerProductProof {
 	n := len(a)
 	transcript.AddToTranscript("n", []byte(strconv.Itoa(n)))
 	Lvec := core.PointVector{}
@@ -26,7 +26,7 @@ func ProveInnerProduct(a, b core.ScalarVector, u core.Point, P *ristretto.Point,
 	transcript.AddToTranscript("G", Gbytes)
 	Hbytes, _ := json.Marshal(H)
 	transcript.AddToTranscript("H", Hbytes)
-	transcript.AddToTranscript("P'", P.Bytes())
+	transcript.AddToTranscript("P'", []byte(P.String()))
 	for n != 1 {
 		np := n / 2
 		aL, aR := a[:np], a[np:]
@@ -40,30 +40,31 @@ func ProveInnerProduct(a, b core.ScalarVector, u core.Point, P *ristretto.Point,
 		L := core.MultiExp(append(aL.Join(bR), cL), append(GR.Join(HL), u))
 		R := core.MultiExp(append(aR.Join(bL), cR), append(GL.Join(HR), u))
 
-		transcript.AddToTranscript("L", L.Bytes())
+		transcript.AddToTranscript("L", []byte(L.String()))
 		Lvec = append(Lvec, L)
-		transcript.AddToTranscript("R", R.Bytes())
+		transcript.AddToTranscript("R",[]byte(R.String()))
 		Rvec = append(Rvec, R)
 
 		u := transcript.CommitToTranscriptScalar("u")
-		uinv := new(ristretto.Scalar).Inverse(u)
+		uinv := new(ristretto.Scalar)
+		uinv.Invert(u)
 
 		for i := 0; i < len(aL); i++ {
-			aL_ := new(ristretto.Scalar).Mul(aL[i], u)
+			aL_ := new(ristretto.Scalar).Multiply(aL[i], u)
-			aL[i] = aL_.Add(aL_, new(ristretto.Scalar).Mul(aR[i], uinv))
+			aL[i] = new(ristretto.Scalar).Add(aL_, new(ristretto.Scalar).Multiply(aR[i], uinv))
-			bL_ := new(ristretto.Scalar).Mul(bL[i], uinv)
+			bL_ := new(ristretto.Scalar).Multiply(bL[i], uinv)
-			bL[i] = bL_.Add(bL_, new(ristretto.Scalar).Mul(bR[i], u))
+			bL[i] = new(ristretto.Scalar).Add(bL_, new(ristretto.Scalar).Multiply(bR[i], u))
 
 			GL[i] = core.MultiExp(core.ScalarVector{uinv, u}, core.GeneratorVector{GL[i], GR[i]})
 			HL[i] = core.MultiExp(core.ScalarVector{u, uinv}, core.GeneratorVector{HL[i], HR[i]})
 		}
 
-		x2 := new(ristretto.Scalar).Square(u)
+		x2 := new(ristretto.Scalar).Multiply(u,u)
-		P_ := new(ristretto.Point).ScalarMult(L, x2)
+		P_ := new(ristretto.Element).ScalarMult(x2,L)
 		P_.Add(P_, P)
-		P_.Add(P_, new(ristretto.Point).ScalarMult(R, new(ristretto.Scalar).Inverse(x2)))
+		P_.Add(P_, new(ristretto.Element).ScalarMult(new(ristretto.Scalar).Invert(x2),R))
 		P = P_
-		transcript.AddToTranscript("P'", P.Bytes())
+		transcript.AddToTranscript("P'", []byte(P.String()))
 
 		a = aL
 		b = bL
@@ -80,7 +81,7 @@ func ProveInnerProduct(a, b core.ScalarVector, u core.Point, P *ristretto.Point,
 }
 
 // Verify checks the given inner product proof
-func Verify(proof InnerProductProof, n int, u, P *ristretto.Point, G, H core.GeneratorVector, transcript *core.Transcript) bool {
+func Verify(proof InnerProductProof, n int, u, P *ristretto.Element, G, H core.GeneratorVector, transcript *core.Transcript) bool {
 	transcript.AddToTranscript("n", []byte(strconv.Itoa(n)))
 	np := n / 2
 
@@ -88,27 +89,28 @@ func Verify(proof InnerProductProof, n int, u, P *ristretto.Point, G, H core.Gen
 	transcript.AddToTranscript("G", Gbytes)
 	Hbytes, _ := json.Marshal(H)
 	transcript.AddToTranscript("H", Hbytes)
-	transcript.AddToTranscript("P'", P.Bytes())
+	transcript.AddToTranscript("P'", []byte(P.String()))
 	for i := range proof.L {
 		GL, GR := G[:np], G[np:]
 		HL, HR := H[:np], H[np:]
 
-		transcript.AddToTranscript("L", proof.L[i].Bytes())
+		transcript.AddToTranscript("L", []byte(proof.L[i].String()))
-		transcript.AddToTranscript("R", proof.R[i].Bytes())
+		transcript.AddToTranscript("R", []byte(proof.R[i].String()))
 		x := transcript.CommitToTranscriptScalar("u")
-		xinv := new(ristretto.Scalar).Inverse(x)
+		xinv := new(ristretto.Scalar)
+		xinv.Invert(x)
 
 		for j := 0; j < np; j++ {
 			GL[j] = core.MultiExp(core.ScalarVector{xinv, x}, core.GeneratorVector{GL[j], GR[j]})
 			HL[j] = core.MultiExp(core.ScalarVector{x, xinv}, core.GeneratorVector{HL[j], HR[j]})
 		}
 
-		x2 := new(ristretto.Scalar).Square(x)
+		x2 := new(ristretto.Scalar).Multiply(x,x)
-		P_ := new(ristretto.Point).ScalarMult(proof.L[i], x2)
+		P_ := new(ristretto.Element).ScalarMult(x2,proof.L[i])
 		P_.Add(P_, P)
-		P_.Add(P_, new(ristretto.Point).ScalarMult(proof.R[i], new(ristretto.Scalar).Inverse(x2)))
+		P_.Add(P_, new(ristretto.Element).ScalarMult(new(ristretto.Scalar).Invert(x2),proof.R[i]))
 		P = P_
-		transcript.AddToTranscript("P'", P.Bytes())
+		transcript.AddToTranscript("P'", []byte(P.String()))
 
 		G = GL
 		H = HL
@@ -118,8 +120,9 @@ func Verify(proof InnerProductProof, n int, u, P *ristretto.Point, G, H core.Gen
 		transcript.AddToTranscript("H", Hbytes)
 		np = np / 2
 	}
-	c := new(ristretto.Scalar).Mul(proof.A, proof.B)
+	c := new(ristretto.Scalar)
+	c.Multiply(proof.A, proof.B)
 	P_ := core.MultiExp(core.ScalarVector{proof.A, proof.B, c}, core.GeneratorVector{G[0], H[0], u})
 	log.Debugf("P:%v\nP':%v\n", P, P_)
-	return P.Equals(P_)
+	return P.Equal(P_) == 1
 }

primitives/bulletproofs/inner_product_test.go

@@ -3,12 +3,13 @@ package bulletproofs
 import (
 	"cwtch.im/tapir/primitives/core"
 	"git.openprivacy.ca/openprivacy/libricochet-go/log"
-	"github.com/bwesterb/go-ristretto"
+	ristretto "github.com/gtank/ristretto255"
 	"testing"
 )
 
+
 func assert(t *testing.T, expected *ristretto.Scalar, actual *ristretto.Scalar) {
-	if expected.Equals(actual) {
+	if expected.Equal(actual) == 1 {
 		t.Logf("inner_product matched: %v", actual)
 	} else {
 		t.Fatalf("c should be %v instead: %v", expected, actual)
@@ -16,8 +17,9 @@ func assert(t *testing.T, expected *ristretto.Scalar, actual *ristretto.Scalar)
 }
 
 func Test_inner_product(t *testing.T) {
-	one := new(ristretto.Scalar).SetOne()
+	one := core.IdentityVector(1)[0]
-	zero := new(ristretto.Scalar).SetZero()
+	zero := new(ristretto.Scalar)
+	zero.Zero()
 	a := core.ScalarVector{one, zero, one, zero}
 	b := core.ScalarVector{zero, one, zero, one}
 	c := core.InnerProduct(a, b)
@@ -26,35 +28,42 @@ func Test_inner_product(t *testing.T) {
 	a = core.ScalarVector{one, one, one, zero}
 	b = core.ScalarVector{one, one, zero, one}
 	c = core.InnerProduct(a, b)
-	assert(t, new(ristretto.Scalar).Add(one, one), c)
+
+	check := new(ristretto.Scalar)
+	check.Add(one,one)
+
+	assert(t, check, c)
 
 }
 
 func TestProveInnerProduct(t *testing.T) {
 	log.SetLevel(log.LevelDebug)
 
-	one := new(ristretto.Scalar).SetOne()
+	one := core.IdentityVector(1)[0]
-	zero := new(ristretto.Scalar).SetZero()
+	zero := new(ristretto.Scalar)
+	zero.Zero()
 	a := core.ScalarVector{one, zero, one, one}
 	b := core.ScalarVector{zero, one, one, one}
 
-	c := core.InnerProduct(a, b)
-	G := make(core.GeneratorVector, 4)
-	H := make(core.GeneratorVector, 4)
-	for i := 0; i < 4; i++ {
-		G[i] = new(ristretto.Point).Rand()
-		H[i] = new(ristretto.Point).Rand()
-	}
-
-	u := new(ristretto.Point).Rand()
-
-	P_ := core.MultiExp(append(a.Join(b), c), append(G.Join(H), u))
-
 	proverTranscript := core.NewTranscript("test_innerproductproof")
 	verifierTranscript := core.NewTranscript("test_innerproductproof")
-	proof := ProveInnerProduct(a, b, u, new(ristretto.Point).Set(P_), core.CopyVector(G), core.CopyVector(H), proverTranscript)
 
-	if Verify(proof, 4, u, new(ristretto.Point).Set(P_), core.CopyVector(G), core.CopyVector(H), verifierTranscript) {
+	G := proverTranscript.CommitToGenerators("G",4)
+	H := proverTranscript.CommitToGenerators("H",4)
+	u := proverTranscript.CommitToGenerator("u")
+
+	verifierTranscript.CommitToGenerators("G",4)
+	verifierTranscript.CommitToGenerators("H",4)
+	verifierTranscript.CommitToGenerator("u")
+
+	c := core.InnerProduct(a,b)
+
+	P_ := core.MultiExp(append(a.Join(b), c), append(core.GeneratorVector(G).Join(core.GeneratorVector(H)), u))
+
+
+	proof := ProveInnerProduct(a, b, u, new(ristretto.Element).Add(new(ristretto.Element).Zero(), P_), core.CopyVector(G), core.CopyVector(H), proverTranscript)
+
+	if Verify(proof, 4, u, P_, core.CopyVector(G), core.CopyVector(H), verifierTranscript) {
 		t.Logf("Inner Product Proof Passed!")
 	} else {
 		t.Logf("%v\n\n%v\n", proverTranscript.OutputTranscriptToAudit(), verifierTranscript.OutputTranscriptToAudit())

primitives/bulletproofs/range_proof.go

@@ -1,32 +1,33 @@
 package bulletproofs
 
 import (
+	"crypto/rand"
 	"cwtch.im/tapir/primitives/core"
 	"git.openprivacy.ca/openprivacy/libricochet-go/log"
-	"github.com/bwesterb/go-ristretto"
+	ristretto "github.com/gtank/ristretto255"
 	"math/big"
 )
 
 // RangeProof encapsulates a proof that V = [0, max) where max is defined by the Setup function
 type RangeProof struct {
-	A            *ristretto.Point
+	A            *ristretto.Element
-	S            *ristretto.Point
+	S            *ristretto.Element
-	T1           *ristretto.Point
+	T1           *ristretto.Element
-	T2           *ristretto.Point
+	T2           *ristretto.Element
 	TauX         *ristretto.Scalar
 	InnerProduct *ristretto.Scalar
 	Mu           *ristretto.Scalar
 	IPP          InnerProductProof
-	V            *ristretto.Point
+	V            *ristretto.Element
 }
 
 // CommitmentsParams encapsulates the commitment parameters for a given range proof
 type CommitmentsParams struct {
 	G   core.GeneratorVector
 	H   core.GeneratorVector
-	u   *ristretto.Point
+	u   *ristretto.Element
-	g   *ristretto.Point
+	g   *ristretto.Element
-	h   *ristretto.Point
+	h   *ristretto.Element
 	max int
 }
 
@@ -43,69 +44,92 @@ func Setup(max int, transcript *core.Transcript) (c CommitmentsParams) {
 	return
 }
 
+func Rand(seed string) *ristretto.Scalar {
+	t := core.NewTranscript(seed)
+	return t.CommitToTranscriptScalar("seed")
+}
+
 // GenerateRangeProof creates a valid rangeproof that value is within [0,max) under the given transcript
-// It returns the rangeproof and a random scalar "gamma" that can be used to open V, the commitement to v vGgH
+// It returns the rangeproof and a random scalar "gamma" that can be used to open V, the commitment to v vGgH
 func GenerateRangeProof(value int32, c CommitmentsParams, transcript *core.Transcript) (RangeProof, *ristretto.Scalar) {
-	one := new(ristretto.Scalar).SetOne()
+	one := core.IdentityVector(1)[0]
-	two := new(ristretto.Scalar).Add(one, one)
+	two := new(ristretto.Scalar)
+	two.Add(one, one)
 	two_n := core.PowerVector(two, c.max)
 
-	gamma := new(ristretto.Scalar).Rand()
+	// Generate a prng to from this transcript and some external randomness
+	// We use this to generate the rest of our private scalars
+	// TODO: move to transcript
+	private := make([]byte,64)
+	rand.Read(private)
+	prngTranscript:= core.NewTranscript("private-transcript")
+	prngTranscript.AddToTranscript("randomness",private)
+	prng := prngTranscript.CommitToPRNG(transcript.OutputTranscriptToAudit())
+
+	gamma := prng.Next()
 
 	aL := valueToVector(value, c.max)
-	aR := core.VectorAddScalar(aL, new(ristretto.Scalar).Neg(one))
+	aR := core.VectorAddScalar(aL, new(ristretto.Scalar).Negate(one))
-	alpha := new(ristretto.Scalar).Rand()
+	alpha := prng.Next()
+
+	vs := new(ristretto.Scalar)
+	b := make([]byte,32)
+	copy(b,big.NewInt(int64(value)).Bytes())
+	vs.Decode(b)
+
 
-	vs := new(ristretto.Scalar).SetBigInt(big.NewInt(int64(value)))
 
 	V := core.MultiExp(core.ScalarVector{gamma, vs}, core.GeneratorVector{c.h, c.g})
 	A := core.MultiExp(append(aL.Join(aR), alpha), append(c.G.Join(c.H), c.h))
+	log.Debugf("vs: %v", vs)
 
 	Sl := make(core.ScalarVector, c.max)
 	Sr := make(core.ScalarVector, c.max)
 	for i := 0; i < c.max; i++ {
-		Sl[i] = new(ristretto.Scalar).Rand()
+		Sl[i] = prng.Next()
-		Sr[i] = new(ristretto.Scalar).Rand()
+		Sr[i] = prng.Next()
 	}
-	p := new(ristretto.Scalar).Rand()
+	p := prng.Next()
 
 	S := core.MultiExp(append(Sl.Join(Sr), p), append(c.G.Join(c.H), c.h))
 
-	transcript.AddToTranscript("A", A.Bytes())
+	transcript.AddToTranscript("A", []byte(A.String()))
-	transcript.AddToTranscript("S", S.Bytes())
+	transcript.AddToTranscript("S",[]byte(S.String()))
 
 	y := transcript.CommitToTranscriptScalar("y")
 	z := transcript.CommitToTranscriptScalar("z")
 
 	y_n := core.PowerVector(y, c.max)
-	z2 := new(ristretto.Scalar).Square(z)
+	z2 := new(ristretto.Scalar).Multiply(z,z)
 
-	l0 := core.VectorAddScalar(aL, new(ristretto.Scalar).Neg(z))
+	l0 := core.VectorAddScalar(aL, new(ristretto.Scalar).Negate(z))
 	//l1 == Sr
 	r0 := core.EntrywiseSum(core.EntryWiseProduct(y_n, core.VectorAddScalar(aR, z)), core.VectorMulScalar(two_n, z2))
 	r1 := core.EntryWiseProduct(Sr, y_n)
 
-	t0 := new(ristretto.Scalar).Add(new(ristretto.Scalar).Mul(z2, vs), delta(y_n, z, c.max))
+	t0 := new(ristretto.Scalar).Add(new(ristretto.Scalar).Multiply(z2, vs), delta(y_n, z, c.max))
-	t1 := new(ristretto.Scalar).Add(core.InnerProduct(Sl, r0), core.InnerProduct(l0, r1))
+	t1 := new(ristretto.Scalar)
+	t1.Add(core.InnerProduct(Sl, r0), core.InnerProduct(l0, r1))
 	t2 := core.InnerProduct(Sl, r1)
 
-	tau1 := new(ristretto.Scalar).Rand()
+	tau1 := prng.Next()
-	tau2 := new(ristretto.Scalar).Rand()
+	tau2 := prng.Next()
 
 	T1 := core.MultiExp(core.ScalarVector{t1, tau1}, core.GeneratorVector{c.g, c.h})
 	T2 := core.MultiExp(core.ScalarVector{t2, tau2}, core.GeneratorVector{c.g, c.h})
 
-	transcript.AddToTranscript("T1", T1.Bytes())
+	transcript.AddToTranscript("T1", []byte(T1.String()))
-	transcript.AddToTranscript("T2", T2.Bytes())
+	transcript.AddToTranscript("T2", []byte(T2.String()))
 
 	x := transcript.CommitToTranscriptScalar("x")
 
 	// T(X) = t0 + t1x + t2x
-	TX := new(ristretto.Scalar).Set(t0)
+	TX := new(ristretto.Scalar)
-	TX.Add(TX, new(ristretto.Scalar).Mul(t1, x))
+	TX.Add(new(ristretto.Scalar).Zero(), t0)
-	TX.Add(TX, new(ristretto.Scalar).Mul(t2, new(ristretto.Scalar).Square(x)))
+	TX.Add(TX, new(ristretto.Scalar).Multiply(t1, x))
+	TX.Add(TX, new(ristretto.Scalar).Multiply(t2, new(ristretto.Scalar).Multiply(x,x)))
 
-	l := core.EntrywiseSum(core.VectorAddScalar(aL, new(ristretto.Scalar).Neg(z)), core.VectorMulScalar(Sl, x))
+	l := core.EntrywiseSum(core.VectorAddScalar(aL, new(ristretto.Scalar).Negate(z)), core.VectorMulScalar(Sl, x))
 	_r := core.EntrywiseSum(core.VectorAddScalar(aR, z), core.VectorMulScalar(Sr, x))
 	r := core.EntrywiseSum(core.EntryWiseProduct(y_n, _r), core.VectorMulScalar(two_n, z2))
 
@@ -113,103 +137,118 @@ func GenerateRangeProof(value int32, c CommitmentsParams, transcript *core.Trans
 
 	log.Debugf("T(X) = %v", TX)
 	log.Debugf("ipp  = %v", iplr)
-	log.Debugf("equal: %v", TX.Equals(iplr))
+	log.Debugf("equal: %v", TX.Equal(iplr) == 1)
 
 	// generate h'
 	H_ := make(core.GeneratorVector, c.max)
 	H_[0] = c.H[0]
 	for i := 1; i < c.max; i++ {
-		H_[i] = new(ristretto.Point).ScalarMult(c.H[i], new(ristretto.Scalar).Inverse(y_n[i]))
+		H_[i] = new(ristretto.Element).ScalarMult(new(ristretto.Scalar).Invert(y_n[i]),c.H[i],)
 	}
 
 	P := core.MultiExp(l.Join(r), c.G.Join(H_))
 	log.Debugf("P: %v", P)
 
-	uP := new(ristretto.Point).Add(P, new(ristretto.Point).ScalarMult(c.u, iplr))
+	uP := new(ristretto.Element).Add(P, new(ristretto.Element).ScalarMult(iplr,c.u))
 	log.Debugf("uP: %v", uP)
-	ipp := ProveInnerProduct(l, r, c.u, new(ristretto.Point).Set(uP), core.CopyVector(c.G), core.CopyVector(H_), transcript)
+	ipp := ProveInnerProduct(l, r, c.u, new(ristretto.Element).Add(new(ristretto.Element).Zero(),uP), core.CopyVector(c.G), core.CopyVector(H_), transcript)
 
-	taux := new(ristretto.Scalar).Mul(tau2, new(ristretto.Scalar).Square(x))
+	taux := new(ristretto.Scalar)
-	taux = taux.Add(taux, new(ristretto.Scalar).Mul(tau1, x))
+	taux.Multiply(tau2, new(ristretto.Scalar).Multiply(x,x))
-	taux = taux.Add(taux, new(ristretto.Scalar).Mul(z2, gamma))
+	taux.Add(taux, new(ristretto.Scalar).Multiply(tau1, x))
+	taux.Add(taux, new(ristretto.Scalar).Multiply(z2, gamma))
 
-	mu := new(ristretto.Scalar).Add(alpha, new(ristretto.Scalar).Mul(p, x))
+	mu := new(ristretto.Scalar)
+	mu.Add(alpha, new(ristretto.Scalar).Multiply(p, x))
 	return RangeProof{A, S, T1, T2, taux, iplr, mu, ipp, V}, gamma
 }
 
 // VerifyRangeProof returns true if the given proof passes all the checks for a given set of commitment parameters
 // and the given transcript
 func VerifyRangeProof(proof RangeProof, c CommitmentsParams, transcript *core.Transcript) bool {
-	one := new(ristretto.Scalar).SetOne()
+	one := core.IdentityVector(1)[0]
-	two := new(ristretto.Scalar).Add(one, one)
+	two := new(ristretto.Scalar)
+	two.Add(one, one)
 	two_n := core.PowerVector(two, c.max)
 
-	transcript.AddToTranscript("A", proof.A.Bytes())
+	transcript.AddToTranscript("A", []byte(proof.A.String()))
-	transcript.AddToTranscript("S", proof.S.Bytes())
+	transcript.AddToTranscript("S",[]byte(proof.S.String()))
 	y := transcript.CommitToTranscriptScalar("y")
 	z := transcript.CommitToTranscriptScalar("z")
-	transcript.AddToTranscript("T1", proof.T1.Bytes())
+	transcript.AddToTranscript("T1", []byte(proof.T1.String()))
-	transcript.AddToTranscript("T2", proof.T2.Bytes())
+	transcript.AddToTranscript("T2", []byte(proof.T2.String()))
 	x := transcript.CommitToTranscriptScalar("x")
 	y_n := core.PowerVector(y, c.max)
 	// generate h'
 	H_ := make(core.GeneratorVector, c.max)
 	H_[0] = c.H[0]
 	for i := 1; i < c.max; i++ {
-		H_[i] = new(ristretto.Point).ScalarMult(c.H[i], new(ristretto.Scalar).Inverse(y_n[i]))
+		H_[i] = new(ristretto.Element).ScalarMult(new(ristretto.Scalar).Invert(y_n[i]),c.H[i],)
 	}
 
 	// check t = t(x) = t0 + t1.x + t1.x^2
 	lhs := core.MultiExp(core.ScalarVector{proof.InnerProduct, proof.TauX}, core.GeneratorVector{c.g, c.h})
-	rhs := core.MultiExp(core.ScalarVector{new(ristretto.Scalar).Square(z), delta(y_n, z, c.max), x, new(ristretto.Scalar).Square(x)}, core.GeneratorVector{proof.V, c.g, proof.T1, proof.T2})
+
+
+	z2 := new(ristretto.Scalar)
+	z2.Multiply(z,z)
+
+	x2 := new(ristretto.Scalar)
+	x2.Multiply(x,x)
+
+	rhs := core.MultiExp(core.ScalarVector{z2, delta(y_n, z, c.max), x, x2}, core.GeneratorVector{proof.V, c.g, proof.T1, proof.T2})
 	log.Debugf("lhs: %v", lhs)
 	log.Debugf("rhs: %v", rhs)
-	log.Debugf("equal: %v", lhs.Equals(rhs))
+	log.Debugf("equal: %v", lhs.Equal(rhs))
 
-	if lhs.Equals(rhs) {
+	if lhs.Equal(rhs) == 1{
 
 		// compute P
 
-		negz := new(ristretto.Scalar).Neg(z)
+		negz := new(ristretto.Scalar).Negate(z)
-		negzG := new(ristretto.Point).SetZero()
+		negzG := new(ristretto.Element).Zero()
 		for _, gen := range c.G {
-			negzG = negzG.Add(negzG, new(ristretto.Point).ScalarMult(gen, negz))
+			negzG = negzG.Add(negzG, new(ristretto.Element).ScalarMult(negz, gen))
 		}
 
-		mul := core.EntrywiseSum(core.VectorMulScalar(y_n, z), core.VectorMulScalar(two_n, new(ristretto.Scalar).Square(z)))
+		mul := core.EntrywiseSum(core.VectorMulScalar(y_n, z), core.VectorMulScalar(two_n, new(ristretto.Scalar).Multiply(z,z)))
 
-		Pr := new(ristretto.Point).Set(proof.A)
+		Pr := new(ristretto.Element).Add(new(ristretto.Element).Zero(),proof.A)
-		Pr = Pr.Add(Pr, new(ristretto.Point).ScalarMult(proof.S, x))
+		Pr = Pr.Add(Pr, new(ristretto.Element).ScalarMult(x,proof.S))
 		Pr = Pr.Add(Pr, negzG)
 		Pr = Pr.Add(Pr, core.MultiExp(mul, H_))
 
-		Pl := new(ristretto.Point).Sub(Pr, new(ristretto.Point).ScalarMult(c.h, proof.Mu))
+		Pl := new(ristretto.Element).Subtract(Pr, new(ristretto.Element).ScalarMult(proof.Mu,c.h))
 		// check inner product
 
-		uP := new(ristretto.Point).Add(Pl, new(ristretto.Point).ScalarMult(c.u, proof.InnerProduct))
+		uP := new(ristretto.Element).Add(Pl, new(ristretto.Element).ScalarMult(proof.InnerProduct, c.u))
 
-		return Verify(proof.IPP, c.max, c.u, new(ristretto.Point).Set(uP), core.CopyVector(c.G), core.CopyVector(H_), transcript)
+		return Verify(proof.IPP, c.max, c.u, new(ristretto.Element).Add(new(ristretto.Element).Zero(),uP), core.CopyVector(c.G), core.CopyVector(H_), transcript)
 	}
 	return false
 }
 
-func delta(y_n core.ScalarVector, z core.Scalar, max int) core.Scalar {
+func delta(y_n core.ScalarVector, z *ristretto.Scalar, max int) *ristretto.Scalar {
-	one := new(ristretto.Scalar).SetOne()
+	one := core.IdentityVector(1)[0]
 	// (z-z^2)
-	z2 := new(ristretto.Scalar).Square(z)
+	z2 := new(ristretto.Scalar).Multiply(z,z)
-	result := new(ristretto.Scalar).Sub(z, z2)
+	result := new(ristretto.Scalar)
+	result.Subtract(z, z2)
 	// (z-z^2) * <1^n,y^n>
-	result.Mul(result, core.InnerProduct(core.IdentityVector(max), y_n))
+	result.Multiply(result, core.InnerProduct(core.IdentityVector(max), y_n))
-	two := new(ristretto.Scalar).Add(one, one)
+	two := new(ristretto.Scalar)
+	two.Add(one, one)
 	two_n := core.PowerVector(two, max)
 	// (z-z^2) * <1^n,y^n> - z^3 *<1n,2n>
-	z3 := new(ristretto.Scalar).Mul(z2, z)
+	z3 := new(ristretto.Scalar).Multiply(z2, z)
-	return result.Sub(result, new(ristretto.Scalar).Mul(z3, core.InnerProduct(core.IdentityVector(max), two_n)))
+	result.Subtract(result, new(ristretto.Scalar).Multiply(z3, core.InnerProduct(core.IdentityVector(max), two_n)))
+	return result
 }
 
 func valueToVector(value int32, max int) core.ScalarVector {
-	one := new(ristretto.Scalar).SetOne()
+	one := core.IdentityVector(1)[0]
-	zero := new(ristretto.Scalar).SetZero()
+	zero := new(ristretto.Scalar)
+	zero.Zero()
 	result := core.ScalarVector{}
 	for len(result) != max {
 		v := value & 0x0001

primitives/bulletproofs/range_proof_test.go

@@ -23,5 +23,4 @@ func TestProove(t *testing.T) {
 		t.Logf("%v\n\n%v\n", proverTranscript.OutputTranscriptToAudit(), verifierTranscript.OutputTranscriptToAudit())
 		t.Fatalf("Failed to Verify Range Proof")
 	}
-
 }

primitives/core/operations.go

@@ -2,29 +2,27 @@ package core
 
 import (
 	"fmt"
-	"github.com/bwesterb/go-ristretto"
+	ristretto "github.com/gtank/ristretto255"
 )
 
-// Scalar is short hand for a ristretto scalar
-type Scalar *ristretto.Scalar
-
-// Point is short hand of a ristretto point
-type Point *ristretto.Point
-
 // ScalarVector explicit type checking
-type ScalarVector []Scalar
+type ScalarVector []*ristretto.Scalar
 
-// PointVector explicit type checking
+// ElementVector explicit type checking
-type PointVector []*ristretto.Point
+type PointVector []*ristretto.Element
 
 // GeneratorVector explicit type checking
-type GeneratorVector []*ristretto.Point
+type GeneratorVector []*ristretto.Element
+
+
+
+
 
 // CopyVector safely copies a vector
 func CopyVector(G GeneratorVector) GeneratorVector {
 	H := make(GeneratorVector, len(G))
 	for i, g := range G {
-		H[i] = new(ristretto.Point).Set(g)
+		H[i] = new(ristretto.Element).Add(new(ristretto.Element).Zero(), g)
 	}
 	return H
 }
@@ -35,23 +33,23 @@ func InnerProduct(a, b ScalarVector) *ristretto.Scalar {
 		panic(fmt.Sprintf("len(a) = %v ;  len(b) = %v;", len(a), len(b)))
 	}
 
-	result := new(ristretto.Scalar).SetZero()
+	result := new(ristretto.Scalar).Zero()
 	for i, ai := range a {
-		result.Add(result, new(ristretto.Scalar).Mul(ai, b[i]))
+		result.Add(result, new(ristretto.Scalar).Multiply(ai, b[i]))
 	}
 	return result
 }
 
 // MultiExp takes in a vector of scalars = {a,b,c...} and a vector of generator = {A,B,C...} and outputs
 // {aA,bB,cC}
-func MultiExp(a ScalarVector, G GeneratorVector) *ristretto.Point {
+func MultiExp(a ScalarVector, G GeneratorVector) *ristretto.Element {
 	if len(a) != len(G) {
 		panic(fmt.Sprintf("len(a) = %v ;  len(b) = %v;", len(a), len(G)))
 	}
-	result := new(ristretto.Point).SetZero()
+	result := new(ristretto.Element).Zero()
 	for i, ai := range a {
-		aG := new(ristretto.Point).ScalarMult(G[i], ai)
+		aG := new(ristretto.Element).ScalarMult(ai, G[i])
-		result = new(ristretto.Point).Add(result, aG)
+		result = new(ristretto.Element).Add(result, aG)
 	}
 	return result
 }
@@ -60,10 +58,10 @@ func MultiExp(a ScalarVector, G GeneratorVector) *ristretto.Point {
 func (a ScalarVector) Join(b ScalarVector) ScalarVector {
 	list := make(ScalarVector, len(a)+len(b))
 	for i := 0; i < len(a); i++ {
-		list[i] = new(ristretto.Scalar).Set(a[i])
+		list[i] = a[i]
 	}
 	for i := len(a); i < len(b)+len(b); i++ {
-		list[i] = new(ristretto.Scalar).Set(b[i-len(a)])
+		list[i] = b[i-len(a)]
 	}
 	return list
 }
@@ -72,10 +70,10 @@ func (a ScalarVector) Join(b ScalarVector) ScalarVector {
 func (a GeneratorVector) Join(b GeneratorVector) GeneratorVector {
 	list := make(GeneratorVector, len(a)+len(b))
 	for i := 0; i < len(a); i++ {
-		list[i] = new(ristretto.Point).Set(a[i])
+		list[i] = a[i]
 	}
 	for i := len(a); i < len(b)+len(b); i++ {
-		list[i] = new(ristretto.Point).Set(b[i-len(a)])
+		list[i] = b[i-len(a)]
 	}
 	return list
 }
@@ -84,7 +82,8 @@ func (a GeneratorVector) Join(b GeneratorVector) GeneratorVector {
 func VectorAddScalar(vector ScalarVector, scalar *ristretto.Scalar) ScalarVector {
 	result := make(ScalarVector, len(vector))
 	for i := range vector {
-		result[i] = new(ristretto.Scalar).Add(vector[i], scalar)
+		result[i] = new(ristretto.Scalar)
+		result[i].Add(vector[i], scalar)
 	}
 	return result
 }
@@ -93,7 +92,8 @@ func VectorAddScalar(vector ScalarVector, scalar *ristretto.Scalar) ScalarVector
 func VectorMulScalar(vector ScalarVector, scalar *ristretto.Scalar) ScalarVector {
 	result := make(ScalarVector, len(vector))
 	for i := range vector {
-		result[i] = new(ristretto.Scalar).Mul(vector[i], scalar)
+		result[i] = new(ristretto.Scalar)
+		result[i].Multiply(vector[i], scalar)
 	}
 	return result
 }
@@ -102,7 +102,8 @@ func VectorMulScalar(vector ScalarVector, scalar *ristretto.Scalar) ScalarVector
 func EntrywiseSum(vector ScalarVector, vector2 ScalarVector) ScalarVector {
 	result := make(ScalarVector, len(vector))
 	for i, v := range vector {
-		result[i] = new(ristretto.Scalar).Add(v, vector2[i])
+		result[i] = new(ristretto.Scalar)
+		result[i].Add(v, vector2[i])
 	}
 	return result
 }
@@ -111,7 +112,8 @@ func EntrywiseSum(vector ScalarVector, vector2 ScalarVector) ScalarVector {
 func EntryWiseProduct(vector ScalarVector, vector2 ScalarVector) ScalarVector {
 	result := make(ScalarVector, len(vector))
 	for i, v := range vector {
-		result[i] = new(ristretto.Scalar).Mul(v, vector2[i])
+		result[i] = new(ristretto.Scalar)
+		result[i].Multiply(v, vector2[i])
 	}
 	return result
 }
@@ -119,8 +121,10 @@ func EntryWiseProduct(vector ScalarVector, vector2 ScalarVector) ScalarVector {
 // IdentityVector is a convenience function to generate a vector v = {1,1,1...1}
 func IdentityVector(n int) ScalarVector {
 	result := make(ScalarVector, n)
+	one := new(ristretto.Scalar)
+	one.Decode([]byte{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})
 	for i := 0; i < n; i++ {
-		result[i] = new(ristretto.Scalar).SetOne()
+		result[i] = one
 	}
 	return result
 }
@@ -128,10 +132,13 @@ func IdentityVector(n int) ScalarVector {
 // PowerVector creates a vector v = {1,x,x^2,x^3..x^n}
 func PowerVector(x *ristretto.Scalar, n int) ScalarVector {
 	result := make(ScalarVector, n)
-	result[0] = new(ristretto.Scalar).SetOne()
+	one := new(ristretto.Scalar)
-	result[1] = new(ristretto.Scalar).Set(x)
+	one.Decode([]byte{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})
-	for i := 1; i < n; i++ {
+	result[0] = one
-		result[i] = new(ristretto.Scalar).Mul(result[i-1], result[1])
+	result[1] = x
+	for i := 2; i < n; i++ {
+		result[i] = new(ristretto.Scalar)
+		result[i].Multiply(result[i-1], x)
 	}
 	return result
-}
+}

primitives/core/transcript.go

@@ -2,18 +2,17 @@ package core
 
 import (
 	"fmt"
-	"github.com/bwesterb/go-ristretto"
+	ristretto "github.com/gtank/ristretto255"
 	"golang.org/x/crypto/sha3"
 	"hash"
 	"io"
 )
 
-// Transcript implements a transcript of a public coin argument.
+// Transcript provides a consistent transcript primitive for our protocols
 //
 // We have the following goals:
-//  - Provide a consisted transcript API for our zero knowledge protocols
 //  - Allow sequential proofs over a common transcript (ensuring a single proof cannot be extracted standalone)
-//  - produce an auditable human-readable transcript.
+//  - be able to produce a human-readable transcript for auditing.
 //
 // The design of this API was inspired by Merlin: https://docs.rs/crate/merlin/
 //
@@ -26,7 +25,7 @@ type Transcript struct {
 // NewTranscript creates a new Transcript with the given Label, the label should be unique to the application
 func NewTranscript(label string) *Transcript {
 	transcript := new(Transcript)
-	transcript.hash = sha3.New256()
+	transcript.hash = sha3.New512()
 	transcript.AddToTranscript("protocol", []byte(label))
 	return transcript
 }
@@ -67,9 +66,11 @@ type PRNG struct {
 
 // Next returns the next "random" scalar from the PRNG
 func (prng *PRNG) Next() *ristretto.Scalar {
-	buf := [32]byte{}
+	buf := [64]byte{}
 	io.ReadFull(prng.prng, buf[:])
-	return new(ristretto.Scalar).SetBytes(&buf)
+	next := new(ristretto.Scalar)
+	next.FromUniformBytes(buf[:])
+	return next
 }
 
 // CommitToPRNG commits the label to the transcript and derives a PRNG from the transcript.
@@ -83,15 +84,13 @@ func (t *Transcript) CommitToPRNG(label string) PRNG {
 }
 
 // CommitToGenerator derives a verifiably random generator from the transcript
-func (t *Transcript) CommitToGenerator(label string) *ristretto.Point {
+func (t *Transcript) CommitToGenerator(label string) *ristretto.Element {
 	c := t.CommitToTranscript(label)
-	cs := [32]byte{}
+	return new(ristretto.Element).FromUniformBytes(c)
-	copy(cs[:], c[:])
-	return new(ristretto.Point).SetElligator(&cs)
 }
 
 // CommitToGenerators derives a set of verifiably random generators from the transcript
-func (t *Transcript) CommitToGenerators(label string, n int) (generators []*ristretto.Point) {
+func (t *Transcript) CommitToGenerators(label string, n int) (generators []*ristretto.Element) {
 	for i := 0; i < n; i++ {
 		generators = append(generators, t.CommitToGenerator(fmt.Sprintf("%v-%d", label, i)))
 	}
@@ -101,7 +100,7 @@ func (t *Transcript) CommitToGenerators(label string, n int) (generators []*rist
 // CommitToTranscriptScalar is a convenience method for CommitToTranscript which returns a ristretto Scalar
 func (t *Transcript) CommitToTranscriptScalar(label string) *ristretto.Scalar {
 	c := t.CommitToTranscript(label)
-	cs := [32]byte{}
+	s := new(ristretto.Scalar)
-	copy(cs[:], c[:])
+	s.FromUniformBytes(c[:])
-	return new(ristretto.Scalar).SetBytes(&cs)
+	return s
 }