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bn128 pairing, r1cs to qap

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README.md

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# go-snark [![Go Report Card](https://goreportcard.com/badge/github.com/arnaucube/go-snark)](https://goreportcard.com/report/github.com/arnaucube/go-snark)
Not finished, work in progress (doing this in my free time, so I don't have much time).
#### Test
```
go test ./... -v
```
## R1CS to Quadratic Arithmetic Program
- `Succinct Non-Interactive Zero Knowledge for a von Neumann Architecture`, Eli Ben-Sasson, Alessandro Chiesa, Eran Tromer, Madars Virza https://eprint.iacr.org/2013/879.pdf
- Vitalik Buterin blog post about QAP https://medium.com/@VitalikButerin/quadratic-arithmetic-programs-from-zero-to-hero-f6d558cea649
- Ariel Gabizon in Zcash blog https://z.cash/blog/snark-explain5
- Lagrange polynomial Wikipedia article https://en.wikipedia.org/wiki/Lagrange_polynomial
#### Usage
- R1CS to QAP
```go
b0 := big.NewFloat(float64(0))
b1 := big.NewFloat(float64(1))
b5 := big.NewFloat(float64(5))
a := [][]*big.Float{
[]*big.Float{b0, b1, b0, b0, b0, b0},
[]*big.Float{b0, b0, b0, b1, b0, b0},
[]*big.Float{b0, b1, b0, b0, b1, b0},
[]*big.Float{b5, b0, b0, b0, b0, b1},
}
b := [][]*big.Float{
[]*big.Float{b0, b1, b0, b0, b0, b0},
[]*big.Float{b0, b1, b0, b0, b0, b0},
[]*big.Float{b1, b0, b0, b0, b0, b0},
[]*big.Float{b1, b0, b0, b0, b0, b0},
}
c := [][]*big.Float{
[]*big.Float{b0, b0, b0, b1, b0, b0},
[]*big.Float{b0, b0, b0, b0, b1, b0},
[]*big.Float{b0, b0, b0, b0, b0, b1},
[]*big.Float{b0, b0, b1, b0, b0, b0},
}
alpha, beta, gamma, z := R1CSToQAP(a, b, c)
fmt.Println(alpha)
fmt.Println(beta)
fmt.Println(gamma)
fmt.Println(z)
/*
out:
alpha: [[-5 9.166666666666666 -5 0.8333333333333334] [8 -11.333333333333332 5 -0.6666666666666666] [0 0 0 0] [-6 9.5 -4 0.5] [4 -7 3.5 -0.5] [-1 1.8333333333333333 -1 0.16666666666666666]]
beta: [[3 -5.166666666666667 2.5 -0.33333333333333337] [-2 5.166666666666667 -2.5 0.33333333333333337] [0 0 0 0] [0 0 0 0] [0 0 0 0] [0 0 0 0]]
gamma: [[0 0 0 0] [0 0 0 0] [-1 1.8333333333333333 -1 0.16666666666666666] [4 -4.333333333333333 1.5 -0.16666666666666666] [-6 9.5 -4 0.5] [4 -7 3.5 -0.5]]
z: [24 -50 35 -10 1]
*/
```
## Bn128
Implementation of the bn128 pairing.
Implementation followng the information and the implementations from:
- `Multiplication and Squaring on Pairing-Friendly
Fields`, Augusto Jun Devegili, Colm Ó hÉigeartaigh, Michael Scott, and Ricardo Dahab https://pdfs.semanticscholar.org/3e01/de88d7428076b2547b60072088507d881bf1.pdf
- `Optimal Pairings`, Frederik Vercauteren https://www.cosic.esat.kuleuven.be/bcrypt/optimal.pdf , https://eprint.iacr.org/2008/096.pdf
- `Double-and-Add with Relative Jacobian
Coordinates`, Björn Fay https://eprint.iacr.org/2014/1014.pdf
- `Fast and Regular Algorithms for Scalar Multiplication
over Elliptic Curves`, Matthieu Rivain https://eprint.iacr.org/2011/338.pdf
- `High-Speed Software Implementation of the Optimal Ate Pairing over Barreto–Naehrig Curves`, Jean-Luc Beuchat, Jorge E. González-Díaz, Shigeo Mitsunari, Eiji Okamoto, Francisco Rodríguez-Henríquez, and Tadanori Teruya https://eprint.iacr.org/2010/354.pdf
- `New software speed records for cryptographic pairings`, Michael Naehrig, Ruben Niederhagen, Peter Schwabe https://cryptojedi.org/papers/dclxvi-20100714.pdf
- `Implementing Cryptographic Pairings over Barreto-Naehrig Curves`, Augusto Jun Devegili, Michael Scott, Ricardo Dahab https://eprint.iacr.org/2007/390.pdf
- https://github.com/zcash/zcash/tree/master/src/snark
- https://github.com/iden3/snarkjs
- https://github.com/ethereum/py_ecc/tree/master/py_ecc/bn128
#### Usage
- Pairing
```go
bn128, err := NewBn128()
assert.Nil(t, err)
big25 := big.NewInt(int64(25))
big30 := big.NewInt(int64(30))
g1a := bn128.G1.MulScalar(bn128.G1.G, big25)
g2a := bn128.G2.MulScalar(bn128.G2.G, big30)
g1b := bn128.G1.MulScalar(bn128.G1.G, big30)
g2b := bn128.G2.MulScalar(bn128.G2.G, big25)
pA, err := bn128.Pairing(g1a, g2a)
assert.Nil(t, err)
pB, err := bn128.Pairing(g1b, g2b)
assert.Nil(t, err)
assert.True(t, bn128.Fq12.Equal(pA, pB))
```

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+ 186
- 0
bn128/README.md

@ -0,0 +1,186 @@
## Bn128
Implementation of the bn128 pairing.
Implementation followng the information and the implementations from:
- `Multiplication and Squaring on Pairing-Friendly
Fields`, Augusto Jun Devegili, Colm Ó hÉigeartaigh, Michael Scott, and Ricardo Dahab https://pdfs.semanticscholar.org/3e01/de88d7428076b2547b60072088507d881bf1.pdf
- `Optimal Pairings`, Frederik Vercauteren https://www.cosic.esat.kuleuven.be/bcrypt/optimal.pdf , https://eprint.iacr.org/2008/096.pdf
- `Double-and-Add with Relative Jacobian
Coordinates`, Björn Fay https://eprint.iacr.org/2014/1014.pdf
- `Fast and Regular Algorithms for Scalar Multiplication
over Elliptic Curves`, Matthieu Rivain https://eprint.iacr.org/2011/338.pdf
- `High-Speed Software Implementation of the Optimal Ate Pairing over Barreto–Naehrig Curves`, Jean-Luc Beuchat, Jorge E. González-Díaz, Shigeo Mitsunari, Eiji Okamoto, Francisco Rodríguez-Henríquez, and Tadanori Teruya https://eprint.iacr.org/2010/354.pdf
- `New software speed records for cryptographic pairings`, Michael Naehrig, Ruben Niederhagen, Peter Schwabe https://cryptojedi.org/papers/dclxvi-20100714.pdf
- `Implementing Cryptographic Pairings over Barreto-Naehrig Curves`, Augusto Jun Devegili, Michael Scott, Ricardo Dahab https://eprint.iacr.org/2007/390.pdf
- https://github.com/zcash/zcash/tree/master/src/snark
- https://github.com/iden3/snarkjs
- https://github.com/ethereum/py_ecc/tree/master/py_ecc/bn128
- [x] Fq, Fq2, Fq6, Fq12 operations
- [x] G1, G2 operations
- [x] preparePairing
- [x] PreComupteG1, PreComupteG2
- [x] DoubleStep, AddStep
- [x] MillerLoop
- [x] Pairing
### Installation
```
go get github.com/arnaucube/bn128
```
#### Usage
- Pairing
```go
bn128, err := NewBn128()
assert.Nil(t, err)
big25 := big.NewInt(int64(25))
big30 := big.NewInt(int64(30))
g1a := bn128.G1.MulScalar(bn128.G1.G, big25)
g2a := bn128.G2.MulScalar(bn128.G2.G, big30)
g1b := bn128.G1.MulScalar(bn128.G1.G, big30)
g2b := bn128.G2.MulScalar(bn128.G2.G, big25)
pA, err := bn128.Pairing(g1a, g2a)
assert.Nil(t, err)
pB, err := bn128.Pairing(g1b, g2b)
assert.Nil(t, err)
assert.True(t, bn128.Fq12.Equal(pA, pB))
```
#### Test
```
go test -v
```
##### Internal operations more deeply
First let's assume that we have these three basic functions to convert integer compositions to big integer compositions:
```go
func iToBig(a int) *big.Int {
return big.NewInt(int64(a))
}
func iiToBig(a, b int) [2]*big.Int {
return [2]*big.Int{iToBig(a), iToBig(b)}
}
func iiiToBig(a, b int) [2]*big.Int {
return [2]*big.Int{iToBig(a), iToBig(b)}
}
```
- Finite Fields (1, 2, 6, 12) operations
```go
// new finite field of order 1
fq1 := NewFq(iToBig(7))
// basic operations of finite field 1
res := fq1.Add(iToBig(4), iToBig(4))
res = fq1.Double(iToBig(5))
res = fq1.Sub(iToBig(5), iToBig(7))
res = fq1.Neg(iToBig(5))
res = fq1.Mul(iToBig(5), iToBig(11))
res = fq1.Inverse(iToBig(4))
res = fq1.Square(iToBig(5))
// new finite field of order 2
nonResidueFq2str := "-1" // i/j
nonResidueFq2, ok := new(big.Int).SetString(nonResidueFq2str, 10)
fq2 := Fq2{fq1, nonResidueFq2}
nonResidueFq6 := iiToBig(9, 1)
// basic operations of finite field of order 2
res := fq2.Add(iiToBig(4, 4), iiToBig(3, 4))
res = fq2.Double(iiToBig(5, 3))
res = fq2.Sub(iiToBig(5, 3), iiToBig(7, 2))
res = fq2.Neg(iiToBig(4, 4))
res = fq2.Mul(iiToBig(4, 4), iiToBig(3, 4))
res = fq2.Inverse(iiToBig(4, 4))
res = fq2.Div(iiToBig(4, 4), iiToBig(3, 4))
res = fq2.Square(iiToBig(4, 4))
// new finite field of order 6
nonResidueFq6 := iiToBig(9, 1) // TODO
fq6 := Fq6{fq2, nonResidueFq6}
// define two new values of Finite Field 6, in order to be able to perform the operations
a := [3][2]*big.Int{
iiToBig(1, 2),
iiToBig(3, 4),
iiToBig(5, 6)}
b := [3][2]*big.Int{
iiToBig(12, 11),
iiToBig(10, 9),
iiToBig(8, 7)}
// basic operations of finite field order 6
res := fq6.Add(a, b)
res = fq6.Sub(a, b)
res = fq6.Mul(a, b)
divRes := fq6.Div(mulRes, b)
// new finite field of order 12
q, ok := new(big.Int).SetString("21888242871839275222246405745257275088696311157297823662689037894645226208583", 10) // i
if !ok {
fmt.Println("error parsing string to big integer")
}
fq1 := NewFq(q)
nonResidueFq2, ok := new(big.Int).SetString("21888242871839275222246405745257275088696311157297823662689037894645226208582", 10) // i
assert.True(t, ok)
nonResidueFq6 := iiToBig(9, 1)
fq2 := Fq2{fq1, nonResidueFq2}
fq6 := Fq6{fq2, nonResidueFq6}
fq12 := Fq12{fq6, fq2, nonResidueFq6}
```
- G1 operations
```go
bn128, err := NewBn128()
assert.Nil(t, err)
r1 := big.NewInt(int64(33))
r2 := big.NewInt(int64(44))
gr1 := bn128.G1.MulScalar(bn128.G1.G, bn128.Fq1.Copy(r1))
gr2 := bn128.G1.MulScalar(bn128.G1.G, bn128.Fq1.Copy(r2))
grsum1 := bn128.G1.Add(gr1, gr2)
r1r2 := bn128.Fq1.Add(r1, r2)
grsum2 := bn128.G1.MulScalar(bn128.G1.G, r1r2)
a := bn128.G1.Affine(grsum1)
b := bn128.G1.Affine(grsum2)
assert.Equal(t, a, b)
assert.Equal(t, "0x2f978c0ab89ebaa576866706b14787f360c4d6c3869efe5a72f7c3651a72ff00", utils.BytesToHex(a[0].Bytes()))
assert.Equal(t, "0x12e4ba7f0edca8b4fa668fe153aebd908d322dc26ad964d4cd314795844b62b2", utils.BytesToHex(a[1].Bytes()))
```
- G2 operations
```go
bn128, err := NewBn128()
assert.Nil(t, err)
r1 := big.NewInt(int64(33))
r2 := big.NewInt(int64(44))
gr1 := bn128.G2.MulScalar(bn128.G2.G, bn128.Fq1.Copy(r1))
gr2 := bn128.G2.MulScalar(bn128.G2.G, bn128.Fq1.Copy(r2))
grsum1 := bn128.G2.Add(gr1, gr2)
r1r2 := bn128.Fq1.Add(r1, r2)
grsum2 := bn128.G2.MulScalar(bn128.G2.G, r1r2)
a := bn128.G2.Affine(grsum1)
b := bn128.G2.Affine(grsum2)
assert.Equal(t, a, b)
```

+ 407
- 0
bn128/bn128.go

@ -0,0 +1,407 @@
package bn128
import (
"bytes"
"errors"
"math/big"
)
type Bn128 struct {
Q *big.Int
Gg1 [2]*big.Int
Gg2 [2][2]*big.Int
NonResidueFq2 *big.Int
NonResidueFq6 [2]*big.Int
Fq1 Fq
Fq2 Fq2
Fq6 Fq6
Fq12 Fq12
G1 G1
G2 G2
LoopCount *big.Int
LoopCountNeg bool
TwoInv *big.Int
CoefB *big.Int
TwistCoefB [2]*big.Int
Twist [2]*big.Int
FrobeniusCoeffsC11 *big.Int
TwistMulByQX [2]*big.Int
TwistMulByQY [2]*big.Int
FinalExp *big.Int
}
func NewBn128() (Bn128, error) {
var b Bn128
q, ok := new(big.Int).SetString("21888242871839275222246405745257275088696311157297823662689037894645226208583", 10) // i
if !ok {
return b, errors.New("err with q")
}
b.Q = q
b.Gg1 = [2]*big.Int{
big.NewInt(int64(1)),
big.NewInt(int64(2)),
}
g2_00, ok := new(big.Int).SetString("10857046999023057135944570762232829481370756359578518086990519993285655852781", 10)
if !ok {
return b, errors.New("err with g2_00")
}
g2_01, ok := new(big.Int).SetString("11559732032986387107991004021392285783925812861821192530917403151452391805634", 10)
if !ok {
return b, errors.New("err with g2_00")
}
g2_10, ok := new(big.Int).SetString("8495653923123431417604973247489272438418190587263600148770280649306958101930", 10)
if !ok {
return b, errors.New("err with g2_00")
}
g2_11, ok := new(big.Int).SetString("4082367875863433681332203403145435568316851327593401208105741076214120093531", 10)
if !ok {
return b, errors.New("err with g2_00")
}
b.Gg2 = [2][2]*big.Int{
[2]*big.Int{
g2_00,
g2_01,
},
[2]*big.Int{
g2_10,
g2_11,
},
}
b.Fq1 = NewFq(q)
b.NonResidueFq2, ok = new(big.Int).SetString("21888242871839275222246405745257275088696311157297823662689037894645226208582", 10) // i
if !ok {
return b, errors.New("err with nonResidueFq2")
}
b.NonResidueFq6 = [2]*big.Int{
big.NewInt(int64(9)),
big.NewInt(int64(1)),
}
b.Fq2 = NewFq2(b.Fq1, b.NonResidueFq2)
b.Fq6 = NewFq6(b.Fq2, b.NonResidueFq6)
b.Fq12 = NewFq12(b.Fq6, b.Fq2, b.NonResidueFq6)
b.G1 = NewG1(b.Fq1, b.Gg1)
b.G2 = NewG2(b.Fq2, b.Gg2)
err := b.preparePairing()
if err != nil {
return b, err
}
return b, nil
}
func BigIsOdd(n *big.Int) bool {
one := big.NewInt(int64(1))
and := new(big.Int).And(n, one)
return bytes.Equal(and.Bytes(), big.NewInt(int64(1)).Bytes())
}
func (bn128 *Bn128) preparePairing() error {
var ok bool
bn128.LoopCount, ok = new(big.Int).SetString("29793968203157093288", 10)
if !ok {
return errors.New("err with LoopCount from string")
}
bn128.LoopCountNeg = false
bn128.TwoInv = bn128.Fq1.Inverse(big.NewInt(int64(2)))
bn128.CoefB = big.NewInt(int64(3))
bn128.Twist = [2]*big.Int{
big.NewInt(int64(9)),
big.NewInt(int64(1)),
}
bn128.TwistCoefB = bn128.Fq2.MulScalar(bn128.Fq2.Inverse(bn128.Twist), bn128.CoefB)
bn128.FrobeniusCoeffsC11, ok = new(big.Int).SetString("21888242871839275222246405745257275088696311157297823662689037894645226208582", 10)
if !ok {
return errors.New("error parsing frobeniusCoeffsC11")
}
a, ok := new(big.Int).SetString("21575463638280843010398324269430826099269044274347216827212613867836435027261", 10)
if !ok {
return errors.New("error parsing a")
}
b, ok := new(big.Int).SetString("10307601595873709700152284273816112264069230130616436755625194854815875713954", 10)
if !ok {
return errors.New("error parsing b")
}
bn128.TwistMulByQX = [2]*big.Int{
a,
b,
}
a, ok = new(big.Int).SetString("2821565182194536844548159561693502659359617185244120367078079554186484126554", 10)
if !ok {
return errors.New("error parsing a")
}
b, ok = new(big.Int).SetString("3505843767911556378687030309984248845540243509899259641013678093033130930403", 10)
if !ok {
return errors.New("error parsing b")
}
bn128.TwistMulByQY = [2]*big.Int{
a,
b,
}
bn128.FinalExp, ok = new(big.Int).SetString("552484233613224096312617126783173147097382103762957654188882734314196910839907541213974502761540629817009608548654680343627701153829446747810907373256841551006201639677726139946029199968412598804882391702273019083653272047566316584365559776493027495458238373902875937659943504873220554161550525926302303331747463515644711876653177129578303191095900909191624817826566688241804408081892785725967931714097716709526092261278071952560171111444072049229123565057483750161460024353346284167282452756217662335528813519139808291170539072125381230815729071544861602750936964829313608137325426383735122175229541155376346436093930287402089517426973178917569713384748081827255472576937471496195752727188261435633271238710131736096299798168852925540549342330775279877006784354801422249722573783561685179618816480037695005515426162362431072245638324744480", 10)
if !ok {
return errors.New("error parsing finalExp")
}
return nil
}
func (bn128 Bn128) Pairing(p1 [3]*big.Int, p2 [3][2]*big.Int) ([2][3][2]*big.Int, error) {
pre1 := bn128.PreComputeG1(p1)
pre2, err := bn128.PreComputeG2(p2)
if err != nil {
return [2][3][2]*big.Int{}, err
}
r1 := bn128.MillerLoop(pre1, pre2)
res := bn128.FinalExponentiation(r1)
return res, nil
}
type AteG1Precomp struct {
Px *big.Int
Py *big.Int
}
func (bn128 Bn128) PreComputeG1(p [3]*big.Int) AteG1Precomp {
pCopy := bn128.G1.Affine(p)
res := AteG1Precomp{
Px: pCopy[0],
Py: pCopy[1],
}
return res
}
type EllCoeffs struct {
Ell0 [2]*big.Int
EllVW [2]*big.Int
EllVV [2]*big.Int
}
type AteG2Precomp struct {
Qx [2]*big.Int
Qy [2]*big.Int
Coeffs []EllCoeffs
}
func (bn128 Bn128) PreComputeG2(p [3][2]*big.Int) (AteG2Precomp, error) {
qCopy := bn128.G2.Affine(p)
res := AteG2Precomp{
qCopy[0],
qCopy[1],
[]EllCoeffs{},
}
r := [3][2]*big.Int{
bn128.Fq2.Copy(qCopy[0]),
bn128.Fq2.Copy(qCopy[1]),
bn128.Fq2.One(),
}
var c EllCoeffs
for i := bn128.LoopCount.BitLen() - 2; i >= 0; i-- {
bit := bn128.LoopCount.Bit(i)
c, r = bn128.DoublingStep(r)
res.Coeffs = append(res.Coeffs, c)
if bit == 1 {
c, r = bn128.MixedAdditionStep(qCopy, r)
res.Coeffs = append(res.Coeffs, c)
}
}
q1 := bn128.G2.Affine(bn128.G2MulByQ(qCopy))
if !bn128.Fq2.Equal(q1[2], bn128.Fq2.One()) {
return res, errors.New("q1[2] != Fq2.One")
}
q2 := bn128.G2.Affine(bn128.G2MulByQ(q1))
if !bn128.Fq2.Equal(q2[2], bn128.Fq2.One()) {
return res, errors.New("q2[2] != Fq2.One")
}
if bn128.LoopCountNeg {
r[1] = bn128.Fq2.Neg(r[1])
}
q2[1] = bn128.Fq2.Neg(q2[1])
c, r = bn128.MixedAdditionStep(q1, r)
res.Coeffs = append(res.Coeffs, c)
c, r = bn128.MixedAdditionStep(q2, r)
res.Coeffs = append(res.Coeffs, c)
return res, nil
}
func (bn128 Bn128) DoublingStep(current [3][2]*big.Int) (EllCoeffs, [3][2]*big.Int) {
x := current[0]
y := current[1]
z := current[2]
a := bn128.Fq2.MulScalar(bn128.Fq2.Mul(x, y), bn128.TwoInv)
b := bn128.Fq2.Square(y)
c := bn128.Fq2.Square(z)
d := bn128.Fq2.Add(c, bn128.Fq2.Add(c, c))
e := bn128.Fq2.Mul(bn128.TwistCoefB, d)
f := bn128.Fq2.Add(e, bn128.Fq2.Add(e, e))
g := bn128.Fq2.MulScalar(bn128.Fq2.Add(b, f), bn128.TwoInv)
h := bn128.Fq2.Sub(
bn128.Fq2.Square(bn128.Fq2.Add(y, z)),
bn128.Fq2.Add(b, c))
i := bn128.Fq2.Sub(e, b)
j := bn128.Fq2.Square(x)
eSqr := bn128.Fq2.Square(e)
current[0] = bn128.Fq2.Mul(a, bn128.Fq2.Sub(b, f))
current[1] = bn128.Fq2.Sub(bn128.Fq2.Sub(bn128.Fq2.Square(g), eSqr),
bn128.Fq2.Add(eSqr, eSqr))
current[2] = bn128.Fq2.Mul(b, h)
res := EllCoeffs{
Ell0: bn128.Fq2.Mul(i, bn128.Twist),
EllVW: bn128.Fq2.Neg(h),
EllVV: bn128.Fq2.Add(j, bn128.Fq2.Add(j, j)),
}
return res, current
}
func (bn128 Bn128) MixedAdditionStep(base, current [3][2]*big.Int) (EllCoeffs, [3][2]*big.Int) {
x1 := current[0]
y1 := current[1]
z1 := current[2]
x2 := base[0]
y2 := base[1]
d := bn128.Fq2.Sub(x1, bn128.Fq2.Mul(x2, z1))
e := bn128.Fq2.Sub(y1, bn128.Fq2.Mul(y2, z1))
f := bn128.Fq2.Square(d)
g := bn128.Fq2.Square(e)
h := bn128.Fq2.Mul(d, f)
i := bn128.Fq2.Mul(x1, f)
j := bn128.Fq2.Sub(
bn128.Fq2.Add(h, bn128.Fq2.Mul(z1, g)),
bn128.Fq2.Add(i, i))
current[0] = bn128.Fq2.Mul(d, j)
current[1] = bn128.Fq2.Sub(
bn128.Fq2.Mul(e, bn128.Fq2.Sub(i, j)),
bn128.Fq2.Mul(h, y1))
current[2] = bn128.Fq2.Mul(z1, h)
coef := EllCoeffs{
Ell0: bn128.Fq2.Mul(
bn128.Twist,
bn128.Fq2.Sub(
bn128.Fq2.Mul(e, x2),
bn128.Fq2.Mul(d, y2))),
EllVW: d,
EllVV: bn128.Fq2.Neg(e),
}
return coef, current
}
func (bn128 Bn128) G2MulByQ(p [3][2]*big.Int) [3][2]*big.Int {
fmx := [2]*big.Int{
p[0][0],
bn128.Fq1.Mul(p[0][1], bn128.Fq1.Copy(bn128.FrobeniusCoeffsC11)),
}
fmy := [2]*big.Int{
p[1][0],
bn128.Fq1.Mul(p[1][1], bn128.Fq1.Copy(bn128.FrobeniusCoeffsC11)),
}
fmz := [2]*big.Int{
p[2][0],
bn128.Fq1.Mul(p[2][1], bn128.Fq1.Copy(bn128.FrobeniusCoeffsC11)),
}
return [3][2]*big.Int{
bn128.Fq2.Mul(bn128.TwistMulByQX, fmx),
bn128.Fq2.Mul(bn128.TwistMulByQY, fmy),
fmz,
}
}
func (bn128 Bn128) MillerLoop(pre1 AteG1Precomp, pre2 AteG2Precomp) [2][3][2]*big.Int {
// https://cryptojedi.org/papers/dclxvi-20100714.pdf
// https://eprint.iacr.org/2008/096.pdf
idx := 0
var c EllCoeffs
f := bn128.Fq12.One()
for i := bn128.LoopCount.BitLen() - 2; i >= 0; i-- {
bit := bn128.LoopCount.Bit(i)
c = pre2.Coeffs[idx]
idx++
f = bn128.Fq12.Square(f)
f = bn128.MulBy024(f,
c.Ell0,
bn128.Fq2.MulScalar(c.EllVW, pre1.Py),
bn128.Fq2.MulScalar(c.EllVV, pre1.Px))
if bit == 1 {
c = pre2.Coeffs[idx]
idx++
f = bn128.MulBy024(
f,
c.Ell0,
bn128.Fq2.MulScalar(c.EllVW, pre1.Py),
bn128.Fq2.MulScalar(c.EllVV, pre1.Px))
}
}
if bn128.LoopCountNeg {
f = bn128.Fq12.Inverse(f)
}
c = pre2.Coeffs[idx]
idx++
f = bn128.MulBy024(
f,
c.Ell0,
bn128.Fq2.MulScalar(c.EllVW, pre1.Py),
bn128.Fq2.MulScalar(c.EllVV, pre1.Px))
c = pre2.Coeffs[idx]
idx++
f = bn128.MulBy024(
f,
c.Ell0,
bn128.Fq2.MulScalar(c.EllVW, pre1.Py),
bn128.Fq2.MulScalar(c.EllVV, pre1.Px))
return f
}
func (bn128 Bn128) MulBy024(a [2][3][2]*big.Int, ell0, ellVW, ellVV [2]*big.Int) [2][3][2]*big.Int {
b := [2][3][2]*big.Int{
[3][2]*big.Int{
ell0,
bn128.Fq2.Zero(),
ellVV,
},
[3][2]*big.Int{
bn128.Fq2.Zero(),
ellVW,
bn128.Fq2.Zero(),
},
}
return bn128.Fq12.Mul(a, b)
}
func (bn128 Bn128) FinalExponentiation(r [2][3][2]*big.Int) [2][3][2]*big.Int {
res := bn128.Fq12.Exp(r, bn128.FinalExp)
return res
}

+ 66
- 0
bn128/bn128_test.go

@ -0,0 +1,66 @@
package bn128
import (
"math/big"
"testing"
"github.com/stretchr/testify/assert"
)
func TestBN128(t *testing.T) {
bn128, err := NewBn128()
assert.Nil(t, err)
big40 := big.NewInt(int64(40))
big75 := big.NewInt(int64(75))
g1a := bn128.G1.MulScalar(bn128.G1.G, bn128.Fq1.Copy(big40))
g2a := bn128.G2.MulScalar(bn128.G2.G, bn128.Fq1.Copy(big75))
g1b := bn128.G1.MulScalar(bn128.G1.G, bn128.Fq1.Copy(big75))
g2b := bn128.G2.MulScalar(bn128.G2.G, bn128.Fq1.Copy(big40))
pre1a := bn128.PreComputeG1(g1a)
pre2a, err := bn128.PreComputeG2(g2a)
assert.Nil(t, err)
pre1b := bn128.PreComputeG1(g1b)
pre2b, err := bn128.PreComputeG2(g2b)
assert.Nil(t, err)
r1 := bn128.MillerLoop(pre1a, pre2a)
r2 := bn128.MillerLoop(pre1b, pre2b)
rbe := bn128.Fq12.Mul(r1, bn128.Fq12.Inverse(r2))
res := bn128.FinalExponentiation(rbe)
a := bn128.Fq12.Affine(res)
b := bn128.Fq12.Affine(bn128.Fq12.One())
assert.True(t, bn128.Fq12.Equal(a, b))
assert.True(t, bn128.Fq12.Equal(res, bn128.Fq12.One()))
}
func TestBN128Pairing(t *testing.T) {
bn128, err := NewBn128()
assert.Nil(t, err)
big25 := big.NewInt(int64(25))
big30 := big.NewInt(int64(30))
g1a := bn128.G1.MulScalar(bn128.G1.G, big25)
g2a := bn128.G2.MulScalar(bn128.G2.G, big30)
g1b := bn128.G1.MulScalar(bn128.G1.G, big30)
g2b := bn128.G2.MulScalar(bn128.G2.G, big25)
pA, err := bn128.Pairing(g1a, g2a)
assert.Nil(t, err)
pB, err := bn128.Pairing(g1b, g2b)
assert.Nil(t, err)
assert.True(t, bn128.Fq12.Equal(pA, pB))
assert.Equal(t, pA[0][0][0].String(), "73680848340331011700282047627232219336104151861349893575958589557226556635706")
assert.Equal(t, bn128.Fq12.Affine(pA)[0][0][0].String(), "8016119724813186033542830391460394070015218389456422587891475873290878009957")
}

+ 129
- 0
bn128/fq.go

@ -0,0 +1,129 @@
package bn128
import (
"bytes"
"math/big"
)
// Fq is the Z field over modulus Q
type Fq struct {
Q *big.Int // Q
}
// NewFq generates a new Fq
func NewFq(q *big.Int) Fq {
return Fq{
q,
}
}
// Zero returns a Zero value on the Fq
func (fq Fq) Zero() *big.Int {
return big.NewInt(int64(0))
}
// One returns a One value on the Fq
func (fq Fq) One() *big.Int {
return big.NewInt(int64(1))
}
// Add performs an addition on the Fq
func (fq Fq) Add(a, b *big.Int) *big.Int {
r := new(big.Int).Add(a, b)
// return new(big.Int).Mod(r, fq.Q)
return r
}
// Double performs a doubling on the Fq
func (fq Fq) Double(a *big.Int) *big.Int {
r := new(big.Int).Add(a, a)
// return new(big.Int).Mod(r, fq.Q)
return r
}
// Sub performs a subtraction on the Fq
func (fq Fq) Sub(a, b *big.Int) *big.Int {
r := new(big.Int).Sub(a, b)
// return new(big.Int).Mod(r, fq.Q)
return r
}
// Neg performs a negation on the Fq
func (fq Fq) Neg(a *big.Int) *big.Int {
m := new(big.Int).Neg(a)
// return new(big.Int).Mod(m, fq.Q)
return m
}
// Mul performs a multiplication on the Fq
func (fq Fq) Mul(a, b *big.Int) *big.Int {
m := new(big.Int).Mul(a, b)
return new(big.Int).Mod(m, fq.Q)
// return m
}
func (fq Fq) MulScalar(base, e *big.Int) *big.Int {
return fq.Mul(base, e)
}
// Inverse returns the inverse on the Fq
func (fq Fq) Inverse(a *big.Int) *big.Int {
return new(big.Int).ModInverse(a, fq.Q)
// q := bigCopy(fq.Q)
// t := big.NewInt(int64(0))
// r := fq.Q
// newt := big.NewInt(int64(0))
// newr := fq.Affine(a)
// for !bytes.Equal(newr.Bytes(), big.NewInt(int64(0)).Bytes()) {
// q := new(big.Int).Div(bigCopy(r), bigCopy(newr))
//
// t = bigCopy(newt)
// newt = fq.Sub(t, fq.Mul(q, newt))
//
// r = bigCopy(newr)
// newr = fq.Sub(r, fq.Mul(q, newr))
// }
// if t.Cmp(big.NewInt(0)) == -1 { // t< 0
// t = fq.Add(t, q)
// }
// return t
}
// Square performs a square operation on the Fq
func (fq Fq) Square(a *big.Int) *big.Int {
m := new(big.Int).Mul(a, a)
return new(big.Int).Mod(m, fq.Q)
}
func (fq Fq) IsZero(a *big.Int) bool {
return bytes.Equal(a.Bytes(), fq.Zero().Bytes())
}
func (fq Fq) Copy(a *big.Int) *big.Int {
return new(big.Int).SetBytes(a.Bytes())
}
func (fq Fq) Affine(a *big.Int) *big.Int {
nq := fq.Neg(fq.Q)
aux := a
if aux.Cmp(big.NewInt(int64(0))) == -1 { // negative value
if aux.Cmp(nq) != 1 { // aux less or equal nq
aux = new(big.Int).Mod(aux, fq.Q)
}
if aux.Cmp(big.NewInt(int64(0))) == -1 { // negative value
aux = new(big.Int).Add(aux, fq.Q)
}
} else {
if aux.Cmp(fq.Q) != -1 { // aux greater or equal nq
aux = new(big.Int).Mod(aux, fq.Q)
}
}
return aux
}
func (fq Fq) Equal(a, b *big.Int) bool {
aAff := fq.Affine(a)
bAff := fq.Affine(b)
return bytes.Equal(aAff.Bytes(), bAff.Bytes())
}

+ 161
- 0
bn128/fq12.go

@ -0,0 +1,161 @@
package bn128
import (
"bytes"
"math/big"
)
// Fq12 uses the same algorithms than Fq2, but with [2][3][2]*big.Int data structure
// Fq12 is Field 12
type Fq12 struct {
F Fq6
Fq2 Fq2
NonResidue [2]*big.Int
}
// NewFq12 generates a new Fq12
func NewFq12(f Fq6, fq2 Fq2, nonResidue [2]*big.Int) Fq12 {
fq12 := Fq12{
f,
fq2,
nonResidue,
}
return fq12
}
// Zero returns a Zero value on the Fq12
func (fq12 Fq12) Zero() [2][3][2]*big.Int {
return [2][3][2]*big.Int{fq12.F.Zero(), fq12.F.Zero()}
}
// One returns a One value on the Fq12
func (fq12 Fq12) One() [2][3][2]*big.Int {
return [2][3][2]*big.Int{fq12.F.One(), fq12.F.Zero()}
}
func (fq12 Fq12) mulByNonResidue(a [3][2]*big.Int) [3][2]*big.Int {
return [3][2]*big.Int{
fq12.Fq2.Mul(fq12.NonResidue, a[2]),
a[0],
a[1],
}
}
// Add performs an addition on the Fq12
func (fq12 Fq12) Add(a, b [2][3][2]*big.Int) [2][3][2]*big.Int {
return [2][3][2]*big.Int{
fq12.F.Add(a[0], b[0]),
fq12.F.Add(a[1], b[1]),
}
}
// Double performs a doubling on the Fq12
func (fq12 Fq12) Double(a [2][3][2]*big.Int) [2][3][2]*big.Int {
return fq12.Add(a, a)
}
// Sub performs a subtraction on the Fq12
func (fq12 Fq12) Sub(a, b [2][3][2]*big.Int) [2][3][2]*big.Int {
return [2][3][2]*big.Int{
fq12.F.Sub(a[0], b[0]),
fq12.F.Sub(a[1], b[1]),
}
}
// Neg performs a negation on the Fq12
func (fq12 Fq12) Neg(a [2][3][2]*big.Int) [2][3][2]*big.Int {
return fq12.Sub(fq12.Zero(), a)
}
// Mul performs a multiplication on the Fq12
func (fq12 Fq12) Mul(a, b [2][3][2]*big.Int) [2][3][2]*big.Int {
// Multiplication and Squaring on Pairing-Friendly .pdf; Section 3 (Karatsuba)
v0 := fq12.F.Mul(a[0], b[0])
v1 := fq12.F.Mul(a[1], b[1])
return [2][3][2]*big.Int{
fq12.F.Add(v0, fq12.mulByNonResidue(v1)),
fq12.F.Sub(
fq12.F.Mul(
fq12.F.Add(a[0], a[1]),
fq12.F.Add(b[0], b[1])),
fq12.F.Add(v0, v1)),
}
}
func (fq12 Fq12) MulScalar(base [2][3][2]*big.Int, e *big.Int) [2][3][2]*big.Int {
// for more possible implementations see g2.go file, at the function g2.MulScalar()
res := fq12.Zero()
rem := e
exp := base
for !bytes.Equal(rem.Bytes(), big.NewInt(int64(0)).Bytes()) {
// if rem % 2 == 1
if bytes.Equal(new(big.Int).Rem(rem, big.NewInt(int64(2))).Bytes(), big.NewInt(int64(1)).Bytes()) {
res = fq12.Add(res, exp)
}
exp = fq12.Double(exp)
rem = rem.Rsh(rem, 1) // rem = rem >> 1
}
return res
}
// Inverse returns the inverse on the Fq12
func (fq12 Fq12) Inverse(a [2][3][2]*big.Int) [2][3][2]*big.Int {
t0 := fq12.F.Square(a[0])
t1 := fq12.F.Square(a[1])
t2 := fq12.F.Sub(t0, fq12.mulByNonResidue(t1))
t3 := fq12.F.Inverse(t2)
return [2][3][2]*big.Int{
fq12.F.Mul(a[0], t3),
fq12.F.Neg(fq12.F.Mul(a[1], t3)),
}
}
// Div performs a division on the Fq12
func (fq12 Fq12) Div(a, b [2][3][2]*big.Int) [2][3][2]*big.Int {
return fq12.Mul(a, fq12.Inverse(b))
}
// Square performs a square operation on the Fq12
func (fq12 Fq12) Square(a [2][3][2]*big.Int) [2][3][2]*big.Int {
ab := fq12.F.Mul(a[0], a[1])
return [2][3][2]*big.Int{
fq12.F.Sub(
fq12.F.Mul(
fq12.F.Add(a[0], a[1]),
fq12.F.Add(
a[0],
fq12.mulByNonResidue(a[1]))),
fq12.F.Add(
ab,
fq12.mulByNonResidue(ab))),
fq12.F.Add(ab, ab),
}
}
func (fq12 Fq12) Exp(base [2][3][2]*big.Int, e *big.Int) [2][3][2]*big.Int {
res := fq12.One()
rem := fq12.Fq2.F.Copy(e)
exp := base
for !bytes.Equal(rem.Bytes(), big.NewInt(int64(0)).Bytes()) {
if BigIsOdd(rem) {
res = fq12.Mul(res, exp)
}
exp = fq12.Square(exp)
rem = new(big.Int).Rsh(rem, 1)
}
return res
}
func (fq12 Fq12) Affine(a [2][3][2]*big.Int) [2][3][2]*big.Int {
return [2][3][2]*big.Int{
fq12.F.Affine(a[0]),
fq12.F.Affine(a[1]),
}
}
func (fq12 Fq12) Equal(a, b [2][3][2]*big.Int) bool {
return fq12.F.Equal(a[0], b[0]) && fq12.F.Equal(a[1], b[1])
}

+ 154
- 0
bn128/fq2.go

@ -0,0 +1,154 @@
package bn128
import (
"math/big"
)
// Fq2 is Field 2
type Fq2 struct {
F Fq
NonResidue *big.Int
}
// NewFq2 generates a new Fq2
func NewFq2(f Fq, nonResidue *big.Int) Fq2 {
fq2 := Fq2{
f,
nonResidue,
}
return fq2
}
// Zero returns a Zero value on the Fq2
func (fq2 Fq2) Zero() [2]*big.Int {
return [2]*big.Int{fq2.F.Zero(), fq2.F.Zero()}
}
// One returns a One value on the Fq2
func (fq2 Fq2) One() [2]*big.Int {
return [2]*big.Int{fq2.F.One(), fq2.F.Zero()}
}
func (fq2 Fq2) mulByNonResidue(a *big.Int) *big.Int {
return fq2.F.Mul(fq2.NonResidue, a)
}
// Add performs an addition on the Fq2
func (fq2 Fq2) Add(a, b [2]*big.Int) [2]*big.Int {
return [2]*big.Int{
fq2.F.Add(a[0], b[0]),
fq2.F.Add(a[1], b[1]),
}
}
// Double performs a doubling on the Fq2
func (fq2 Fq2) Double(a [2]*big.Int) [2]*big.Int {
return fq2.Add(a, a)
}
// Sub performs a subtraction on the Fq2
func (fq2 Fq2) Sub(a, b [2]*big.Int) [2]*big.Int {
return [2]*big.Int{
fq2.F.Sub(a[0], b[0]),
fq2.F.Sub(a[1], b[1]),
}
}
// Neg performs a negation on the Fq2
func (fq2 Fq2) Neg(a [2]*big.Int) [2]*big.Int {
return fq2.Sub(fq2.Zero(), a)
}
// Mul performs a multiplication on the Fq2
func (fq2 Fq2) Mul(a, b [2]*big.Int) [2]*big.Int {
// Multiplication and Squaring on Pairing-Friendly.pdf; Section 3 (Karatsuba)
// https://pdfs.semanticscholar.org/3e01/de88d7428076b2547b60072088507d881bf1.pdf
v0 := fq2.F.Mul(a[0], b[0])
v1 := fq2.F.Mul(a[1], b[1])
return [2]*big.Int{
fq2.F.Add(v0, fq2.mulByNonResidue(v1)),
fq2.F.Sub(
fq2.F.Mul(
fq2.F.Add(a[0], a[1]),
fq2.F.Add(b[0], b[1])),
fq2.F.Add(v0, v1)),
}
}
func (fq2 Fq2) MulScalar(p [2]*big.Int, e *big.Int) [2]*big.Int {
// for more possible implementations see g2.go file, at the function g2.MulScalar()
q := fq2.Zero()
d := fq2.F.Copy(e)
r := p
foundone := false
for i := d.BitLen(); i >= 0; i-- {
if foundone {
q = fq2.Double(q)
}
if d.Bit(i) == 1 {
foundone = true
q = fq2.Add(q, r)
}
}
return q
}
// Inverse returns the inverse on the Fq2
func (fq2 Fq2) Inverse(a [2]*big.Int) [2]*big.Int {
// High-Speed Software Implementation of the Optimal Ate Pairing over Barreto–Naehrig Curves .pdf
// https://eprint.iacr.org/2010/354.pdf , algorithm 8
t0 := fq2.F.Square(a[0])
t1 := fq2.F.Square(a[1])
t2 := fq2.F.Sub(t0, fq2.mulByNonResidue(t1))
t3 := fq2.F.Inverse(t2)
return [2]*big.Int{
fq2.F.Mul(a[0], t3),
fq2.F.Neg(fq2.F.Mul(a[1], t3)),
}
}
// Div performs a division on the Fq2
func (fq2 Fq2) Div(a, b [2]*big.Int) [2]*big.Int {
return fq2.Mul(a, fq2.Inverse(b))
}
// Square performs a square operation on the Fq2
func (fq2 Fq2) Square(a [2]*big.Int) [2]*big.Int {
// https://pdfs.semanticscholar.org/3e01/de88d7428076b2547b60072088507d881bf1.pdf , complex squaring
ab := fq2.F.Mul(a[0], a[1])
return [2]*big.Int{
fq2.F.Sub(
fq2.F.Mul(
fq2.F.Add(a[0], a[1]),
fq2.F.Add(
a[0],
fq2.mulByNonResidue(a[1]))),
fq2.F.Add(
ab,
fq2.mulByNonResidue(ab))),
fq2.F.Add(ab, ab),
}
}
func (fq2 Fq2) IsZero(a [2]*big.Int) bool {
return fq2.F.IsZero(a[0]) && fq2.F.IsZero(a[1])
}
func (fq2 Fq2) Affine(a [2]*big.Int) [2]*big.Int {
return [2]*big.Int{
fq2.F.Affine(a[0]),
fq2.F.Affine(a[1]),
}
}
func (fq2 Fq2) Equal(a, b [2]*big.Int) bool {
return fq2.F.Equal(a[0], b[0]) && fq2.F.Equal(a[1], b[1])
}
func (fq2 Fq2) Copy(a [2]*big.Int) [2]*big.Int {
return [2]*big.Int{
fq2.F.Copy(a[0]),
fq2.F.Copy(a[1]),
}
}

+ 192
- 0
bn128/fq6.go

@ -0,0 +1,192 @@
package bn128
import (
"bytes"
"math/big"
)
// Fq6 is Field 6
type Fq6 struct {
F Fq2
NonResidue [2]*big.Int
}
// NewFq6 generates a new Fq6
func NewFq6(f Fq2, nonResidue [2]*big.Int) Fq6 {
fq6 := Fq6{
f,
nonResidue,
}
return fq6
}
// Zero returns a Zero value on the Fq6
func (fq6 Fq6) Zero() [3][2]*big.Int {
return [3][2]*big.Int{fq6.F.Zero(), fq6.F.Zero(), fq6.F.Zero()}
}
// One returns a One value on the Fq6
func (fq6 Fq6) One() [3][2]*big.Int {
return [3][2]*big.Int{fq6.F.One(), fq6.F.Zero(), fq6.F.Zero()}
}
func (fq6 Fq6) mulByNonResidue(a [2]*big.Int) [2]*big.Int {
return fq6.F.Mul(fq6.NonResidue, a)
}
// Add performs an addition on the Fq6
func (fq6 Fq6) Add(a, b [3][2]*big.Int) [3][2]*big.Int {
return [3][2]*big.Int{
fq6.F.Add(a[0], b[0]),
fq6.F.Add(a[1], b[1]),
fq6.F.Add(a[2], b[2]),
}
}
func (fq6 Fq6) Double(a [3][2]*big.Int) [3][2]*big.Int {
return fq6.Add(a, a)
}
// Sub performs a subtraction on the Fq6
func (fq6 Fq6) Sub(a, b [3][2]*big.Int) [3][2]*big.Int {
return [3][2]*big.Int{
fq6.F.Sub(a[0], b[0]),
fq6.F.Sub(a[1], b[1]),
fq6.F.Sub(a[2], b[2]),
}
}
// Neg performs a negation on the Fq6
func (fq6 Fq6) Neg(a [3][2]*big.Int) [3][2]*big.Int {
return fq6.Sub(fq6.Zero(), a)
}
// Mul performs a multiplication on the Fq6
func (fq6 Fq6) Mul(a, b [3][2]*big.Int) [3][2]*big.Int {
v0 := fq6.F.Mul(a[0], b[0])
v1 := fq6.F.Mul(a[1], b[1])
v2 := fq6.F.Mul(a[2], b[2])
return [3][2]*big.Int{
fq6.F.Add(
v0,
fq6.mulByNonResidue(
fq6.F.Sub(
fq6.F.Mul(
fq6.F.Add(a[1], a[2]),
fq6.F.Add(b[1], b[2])),
fq6.F.Add(v1, v2)))),
fq6.F.Add(
fq6.F.Sub(
fq6.F.Mul(
fq6.F.Add(a[0], a[1]),
fq6.F.Add(b[0], b[1])),
fq6.F.Add(v0, v1)),
fq6.mulByNonResidue(v2)),
fq6.F.Add(
fq6.F.Sub(
fq6.F.Mul(
fq6.F.Add(a[0], a[2]),
fq6.F.Add(b[0], b[2])),
fq6.F.Add(v0, v2)),
v1),
}
}
func (fq6 Fq6) MulScalar(base [3][2]*big.Int, e *big.Int) [3][2]*big.Int {
// for more possible implementations see g2.go file, at the function g2.MulScalar()
res := fq6.Zero()
rem := e
exp := base
for !bytes.Equal(rem.Bytes(), big.NewInt(int64(0)).Bytes()) {
// if rem % 2 == 1
if bytes.Equal(new(big.Int).Rem(rem, big.NewInt(int64(2))).Bytes(), big.NewInt(int64(1)).Bytes()) {
res = fq6.Add(res, exp)
}
exp = fq6.Double(exp)
rem = rem.Rsh(rem, 1) // rem = rem >> 1
}
return res
}
// Inverse returns the inverse on the Fq6
func (fq6 Fq6) Inverse(a [3][2]*big.Int) [3][2]*big.Int {
t0 := fq6.F.Square(a[0])
t1 := fq6.F.Square(a[1])
t2 := fq6.F.Square(a[2])
t3 := fq6.F.Mul(a[0], a[1])
t4 := fq6.F.Mul(a[0], a[2])
t5 := fq6.F.Mul(a[1], a[2])
c0 := fq6.F.Sub(t0, fq6.mulByNonResidue(t5))
c1 := fq6.F.Sub(fq6.mulByNonResidue(t2), t3)
c2 := fq6.F.Sub(t1, t4)
t6 := fq6.F.Inverse(
fq6.F.Add(
fq6.F.Mul(a[0], c0),
fq6.mulByNonResidue(
fq6.F.Add(
fq6.F.Mul(a[2], c1),
fq6.F.Mul(a[1], c2)))))
return [3][2]*big.Int{
fq6.F.Mul(t6, c0),
fq6.F.Mul(t6, c1),
fq6.F.Mul(t6, c2),
}
}
// Div performs a division on the Fq6
func (fq6 Fq6) Div(a, b [3][2]*big.Int) [3][2]*big.Int {
return fq6.Mul(a, fq6.Inverse(b))
}
// Square performs a square operation on the Fq6
func (fq6 Fq6) Square(a [3][2]*big.Int) [3][2]*big.Int {
s0 := fq6.F.Square(a[0])
ab := fq6.F.Mul(a[0], a[1])
s1 := fq6.F.Add(ab, ab)
s2 := fq6.F.Square(
fq6.F.Add(
fq6.F.Sub(a[0], a[1]),
a[2]))
bc := fq6.F.Mul(a[1], a[2])
s3 := fq6.F.Add(bc, bc)
s4 := fq6.F.Square(a[2])
return [3][2]*big.Int{
fq6.F.Add(
s0,
fq6.mulByNonResidue(s3)),
fq6.F.Add(
s1,
fq6.mulByNonResidue(s4)),
fq6.F.Sub(
fq6.F.Add(
fq6.F.Add(s1, s2),
s3),
fq6.F.Add(s0, s4)),
}
}
func (fq6 Fq6) Affine(a [3][2]*big.Int) [3][2]*big.Int {
return [3][2]*big.Int{
fq6.F.Affine(a[0]),
fq6.F.Affine(a[1]),
fq6.F.Affine(a[2]),
}
}
func (fq6 Fq6) Equal(a, b [3][2]*big.Int) bool {
return fq6.F.Equal(a[0], b[0]) && fq6.F.Equal(a[1], b[1]) && fq6.F.Equal(a[2], b[2])
}
func (fq6 Fq6) Copy(a [3][2]*big.Int) [3][2]*big.Int {
return [3][2]*big.Int{
fq6.F.Copy(a[0]),
fq6.F.Copy(a[1]),
fq6.F.Copy(a[2]),
}
}

+ 160
- 0
bn128/fqn_test.go

@ -0,0 +1,160 @@
package bn128
import (
"math/big"
"testing"
"github.com/stretchr/testify/assert"
)
func iToBig(a int) *big.Int {
return big.NewInt(int64(a))
}
func iiToBig(a, b int) [2]*big.Int {
return [2]*big.Int{iToBig(a), iToBig(b)}
}
func iiiToBig(a, b int) [2]*big.Int {
return [2]*big.Int{iToBig(a), iToBig(b)}
}
func TestFq1(t *testing.T) {
fq1 := NewFq(iToBig(7))
res := fq1.Add(iToBig(4), iToBig(4))
assert.Equal(t, iToBig(1), fq1.Affine(res))
res = fq1.Double(iToBig(5))
assert.Equal(t, iToBig(3), fq1.Affine(res))
res = fq1.Sub(iToBig(5), iToBig(7))
assert.Equal(t, iToBig(5), fq1.Affine(res))
res = fq1.Neg(iToBig(5))
assert.Equal(t, iToBig(2), fq1.Affine(res))
res = fq1.Mul(iToBig(5), iToBig(11))
assert.Equal(t, iToBig(6), fq1.Affine(res))
res = fq1.Inverse(iToBig(4))
assert.Equal(t, iToBig(2), res)
res = fq1.Square(iToBig(5))
assert.Equal(t, iToBig(4), res)
}
func TestFq2(t *testing.T) {
fq1 := NewFq(iToBig(7))
nonResidueFq2str := "-1" // i/j
nonResidueFq2, ok := new(big.Int).SetString(nonResidueFq2str, 10)
assert.True(t, ok)
assert.Equal(t, nonResidueFq2.String(), nonResidueFq2str)
fq2 := Fq2{fq1, nonResidueFq2}
res := fq2.Add(iiToBig(4, 4), iiToBig(3, 4))
assert.Equal(t, iiToBig(0, 1), fq2.Affine(res))
res = fq2.Double(iiToBig(5, 3))
assert.Equal(t, iiToBig(3, 6), fq2.Affine(res))
res = fq2.Sub(iiToBig(5, 3), iiToBig(7, 2))
assert.Equal(t, iiToBig(5, 1), fq2.Affine(res))
res = fq2.Neg(iiToBig(4, 4))
assert.Equal(t, iiToBig(3, 3), fq2.Affine(res))
res = fq2.Mul(iiToBig(4, 4), iiToBig(3, 4))
assert.Equal(t, iiToBig(3, 0), fq2.Affine(res))
res = fq2.Inverse(iiToBig(4, 4))
assert.Equal(t, iiToBig(1, 6), fq2.Affine(res))
res = fq2.Square(iiToBig(4, 4))
assert.Equal(t, iiToBig(0, 4), fq2.Affine(res))
res2 := fq2.Mul(iiToBig(4, 4), iiToBig(4, 4))
assert.Equal(t, fq2.Affine(res), fq2.Affine(res2))
assert.True(t, fq2.Equal(res, res2))
res = fq2.Square(iiToBig(3, 5))
assert.Equal(t, iiToBig(5, 2), fq2.Affine(res))
res2 = fq2.Mul(iiToBig(3, 5), iiToBig(3, 5))
assert.Equal(t, fq2.Affine(res), fq2.Affine(res2))
}
func TestFq6(t *testing.T) {
bn128, err := NewBn128()
assert.Nil(t, err)
a := [3][2]*big.Int{
iiToBig(1, 2),
iiToBig(3, 4),
iiToBig(5, 6)}
b := [3][2]*big.Int{
iiToBig(12, 11),
iiToBig(10, 9),
iiToBig(8, 7)}
mulRes := bn128.Fq6.Mul(a, b)
divRes := bn128.Fq6.Div(mulRes, b)
assert.Equal(t, bn128.Fq6.Affine(a), bn128.Fq6.Affine(divRes))
}
func TestFq12(t *testing.T) {
q, ok := new(big.Int).SetString("21888242871839275222246405745257275088696311157297823662689037894645226208583", 10) // i
assert.True(t, ok)
fq1 := NewFq(q)
nonResidueFq2, ok := new(big.Int).SetString("21888242871839275222246405745257275088696311157297823662689037894645226208582", 10) // i
assert.True(t, ok)
nonResidueFq6 := iiToBig(9, 1)
fq2 := Fq2{fq1, nonResidueFq2}
fq6 := Fq6{fq2, nonResidueFq6}
fq12 := Fq12{fq6, fq2, nonResidueFq6}
a := [2][3][2]*big.Int{
{
iiToBig(1, 2),
iiToBig(3, 4),
iiToBig(5, 6),
},
{
iiToBig(7, 8),
iiToBig(9, 10),
iiToBig(11, 12),
},
}
b := [2][3][2]*big.Int{
{
iiToBig(12, 11),
iiToBig(10, 9),
iiToBig(8, 7),
},
{
iiToBig(6, 5),
iiToBig(4, 3),
iiToBig(2, 1),
},
}
res := fq12.Add(a, b)
assert.Equal(t,
[2][3][2]*big.Int{
{
iiToBig(13, 13),
iiToBig(13, 13),
iiToBig(13, 13),
},
{
iiToBig(13, 13),
iiToBig(13, 13),
iiToBig(13, 13),
},
},
res)
mulRes := fq12.Mul(a, b)
divRes := fq12.Div(mulRes, b)
assert.Equal(t, fq12.Affine(a), fq12.Affine(divRes))
}

+ 191
- 0
bn128/g1.go

@ -0,0 +1,191 @@
package bn128
import (
"math/big"
)
type G1 struct {
F Fq
G [3]*big.Int
}
func NewG1(f Fq, g [2]*big.Int) G1 {
var g1 G1
g1.F = f
g1.G = [3]*big.Int{
g[0],
g[1],
g1.F.One(),
}
return g1
}
func (g1 G1) Zero() [2]*big.Int {
return [2]*big.Int{g1.F.Zero(), g1.F.Zero()}
}
func (g1 G1) IsZero(p [3]*big.Int) bool {
return g1.F.IsZero(p[2])
}
func (g1 G1) Add(p1, p2 [3]*big.Int) [3]*big.Int {
// https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates
// https://github.com/zcash/zcash/blob/master/src/snark/libsnark/algebra/curves/alt_bn128/alt_bn128_g1.cpp#L208
// http://hyperelliptic.org/EFD/g1p/auto-code/shortw/jacobian-0/addition/add-2007-bl.op3
if g1.IsZero(p1) {
return p2
}
if g1.IsZero(p2) {
return p1
}
x1 := p1[0]
y1 := p1[1]
z1 := p1[2]
x2 := p2[0]
y2 := p2[1]
z2 := p2[2]
z1z1 := g1.F.Square(z1)
z2z2 := g1.F.Square(z2)
u1 := g1.F.Mul(x1, z2z2)
u2 := g1.F.Mul(x2, z1z1)
t0 := g1.F.Mul(z2, z2z2)
s1 := g1.F.Mul(y1, t0)
t1 := g1.F.Mul(z1, z1z1)
s2 := g1.F.Mul(y2, t1)
h := g1.F.Sub(u2, u1)
t2 := g1.F.Add(h, h)
i := g1.F.Square(t2)
j := g1.F.Mul(h, i)
t3 := g1.F.Sub(s2, s1)
r := g1.F.Add(t3, t3)
v := g1.F.Mul(u1, i)
t4 := g1.F.Square(r)
t5 := g1.F.Add(v, v)
t6 := g1.F.Sub(t4, j)
x3 := g1.F.Sub(t6, t5)
t7 := g1.F.Sub(v, x3)
t8 := g1.F.Mul(s1, j)
t9 := g1.F.Add(t8, t8)
t10 := g1.F.Mul(r, t7)
y3 := g1.F.Sub(t10, t9)
t11 := g1.F.Add(z1, z2)
t12 := g1.F.Square(t11)
t13 := g1.F.Sub(t12, z1z1)
t14 := g1.F.Sub(t13, z2z2)
z3 := g1.F.Mul(t14, h)
return [3]*big.Int{x3, y3, z3}
}
func (g1 G1) Neg(p [3]*big.Int) [3]*big.Int {
return [3]*big.Int{
p[0],
g1.F.Neg(p[1]),
p[2],
}
}
func (g1 G1) Sub(a, b [3]*big.Int) [3]*big.Int {
return g1.Add(a, g1.Neg(b))
}
func (g1 G1) Double(p [3]*big.Int) [3]*big.Int {
// https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates
// http://hyperelliptic.org/EFD/g1p/auto-code/shortw/jacobian-0/doubling/dbl-2009-l.op3
// https://github.com/zcash/zcash/blob/master/src/snark/libsnark/algebra/curves/alt_bn128/alt_bn128_g1.cpp#L325
if g1.IsZero(p) {
return p
}
a := g1.F.Square(p[0])
b := g1.F.Square(p[1])
c := g1.F.Square(b)
t0 := g1.F.Add(p[0], b)
t1 := g1.F.Square(t0)
t2 := g1.F.Sub(t1, a)
t3 := g1.F.Sub(t2, c)
d := g1.F.Double(t3)
e := g1.F.Add(g1.F.Add(a, a), a)
f := g1.F.Square(e)
t4 := g1.F.Double(d)
x3 := g1.F.Sub(f, t4)
t5 := g1.F.Sub(d, x3)
twoC := g1.F.Add(c, c)
fourC := g1.F.Add(twoC, twoC)
t6 := g1.F.Add(fourC, fourC)
t7 := g1.F.Mul(e, t5)
y3 := g1.F.Sub(t7, t6)
t8 := g1.F.Mul(p[1], p[2])
z3 := g1.F.Double(t8)
return [3]*big.Int{x3, y3, z3}
}
func (g1 G1) MulScalar(p [3]*big.Int, e *big.Int) [3]*big.Int {
// https://en.wikipedia.org/wiki/Elliptic_curve_point_multiplication#Double-and-add
// for more possible implementations see g2.go file, at the function g2.MulScalar()
q := [3]*big.Int{g1.F.Zero(), g1.F.Zero(), g1.F.Zero()}
d := g1.F.Copy(e)
r := p
for i := d.BitLen() - 1; i >= 0; i-- {
q = g1.Double(q)
if d.Bit(i) == 1 {
q = g1.Add(q, r)
}
}
return q
}
func (g1 G1) Affine(p [3]*big.Int) [2]*big.Int {
if g1.IsZero(p) {
return g1.Zero()
}
zinv := g1.F.Inverse(p[2])
zinv2 := g1.F.Square(zinv)
x := g1.F.Mul(p[0], zinv2)
zinv3 := g1.F.Mul(zinv2, zinv)
y := g1.F.Mul(p[1], zinv3)
return [2]*big.Int{x, y}
}
func (g1 G1) Equal(p1, p2 [3]*big.Int) bool {
if g1.IsZero(p1) {
return g1.IsZero(p2)
}
if g1.IsZero(p2) {
return g1.IsZero(p1)
}
z1z1 := g1.F.Square(p1[2])
z2z2 := g1.F.Square(p2[2])
u1 := g1.F.Mul(p1[0], z2z2)
u2 := g1.F.Mul(p2[0], z1z1)
z1cub := g1.F.Mul(p1[2], z1z1)
z2cub := g1.F.Mul(p2[2], z2z2)
s1 := g1.F.Mul(p1[1], z2cub)
s2 := g1.F.Mul(p2[1], z1cub)
return g1.F.Equal(u1, u2) && g1.F.Equal(s1, s2)
}

+ 31
- 0
bn128/g1_test.go

@ -0,0 +1,31 @@
package bn128
import (
"math/big"
"testing"
"github.com/arnaucube/cryptofun/utils"
"github.com/stretchr/testify/assert"
)
func TestG1(t *testing.T) {
bn128, err := NewBn128()
assert.Nil(t, err)
r1 := big.NewInt(int64(33))
r2 := big.NewInt(int64(44))
gr1 := bn128.G1.MulScalar(bn128.G1.G, bn128.Fq1.Copy(r1))
gr2 := bn128.G1.MulScalar(bn128.G1.G, bn128.Fq1.Copy(r2))
grsum1 := bn128.G1.Add(gr1, gr2) // g*33 + g*44
r1r2 := bn128.Fq1.Add(r1, r2) // 33 + 44
grsum2 := bn128.G1.MulScalar(bn128.G1.G, r1r2) // g * (33+44)
assert.True(t, bn128.G1.Equal(grsum1, grsum2))
a := bn128.G1.Affine(grsum1)
b := bn128.G1.Affine(grsum2)
assert.Equal(t, a, b)
assert.Equal(t, "0x2f978c0ab89ebaa576866706b14787f360c4d6c3869efe5a72f7c3651a72ff00", utils.BytesToHex(a[0].Bytes()))
assert.Equal(t, "0x12e4ba7f0edca8b4fa668fe153aebd908d322dc26ad964d4cd314795844b62b2", utils.BytesToHex(a[1].Bytes()))
}

+ 221
- 0
bn128/g2.go

@ -0,0 +1,221 @@
package bn128
import (
"math/big"
)
type G2 struct {
F Fq2
G [3][2]*big.Int
}
func NewG2(f Fq2, g [2][2]*big.Int) G2 {
var g2 G2
g2.F = f
g2.G = [3][2]*big.Int{
g[0],
g[1],
g2.F.One(),
}
return g2
}
func (g2 G2) Zero() [3][2]*big.Int {
return [3][2]*big.Int{g2.F.Zero(), g2.F.One(), g2.F.Zero()}
}
func (g2 G2) IsZero(p [3][2]*big.Int) bool {
return g2.F.IsZero(p[2])
}
func (g2 G2) Add(p1, p2 [3][2]*big.Int) [3][2]*big.Int {
// https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates
// https://github.com/zcash/zcash/blob/master/src/snark/libsnark/algebra/curves/alt_bn128/alt_bn128_g2.cpp#L208
// http://hyperelliptic.org/EFD/g2p/auto-code/shortw/jacobian-0/addition/add-2007-bl.op3
if g2.IsZero(p1) {
return p2
}
if g2.IsZero(p2) {
return p1
}
x1 := p1[0]
y1 := p1[1]
z1 := p1[2]
x2 := p2[0]
y2 := p2[1]
z2 := p2[2]
z1z1 := g2.F.Square(z1)
z2z2 := g2.F.Square(z2)
u1 := g2.F.Mul(x1, z2z2)
u2 := g2.F.Mul(x2, z1z1)
t0 := g2.F.Mul(z2, z2z2)
s1 := g2.F.Mul(y1, t0)
t1 := g2.F.Mul(z1, z1z1)
s2 := g2.F.Mul(y2, t1)
h := g2.F.Sub(u2, u1)
t2 := g2.F.Add(h, h)
i := g2.F.Square(t2)
j := g2.F.Mul(h, i)
t3 := g2.F.Sub(s2, s1)
r := g2.F.Add(t3, t3)
v := g2.F.Mul(u1, i)
t4 := g2.F.Square(r)
t5 := g2.F.Add(v, v)
t6 := g2.F.Sub(t4, j)
x3 := g2.F.Sub(t6, t5)
t7 := g2.F.Sub(v, x3)
t8 := g2.F.Mul(s1, j)
t9 := g2.F.Add(t8, t8)
t10 := g2.F.Mul(r, t7)
y3 := g2.F.Sub(t10, t9)
t11 := g2.F.Add(z1, z2)
t12 := g2.F.Square(t11)
t13 := g2.F.Sub(t12, z1z1)
t14 := g2.F.Sub(t13, z2z2)
z3 := g2.F.Mul(t14, h)
return [3][2]*big.Int{x3, y3, z3}
}
func (g2 G2) Neg(p [3][2]*big.Int) [3][2]*big.Int {
return [3][2]*big.Int{
p[0],
g2.F.Neg(p[1]),
p[2],
}
}
func (g2 G2) Sub(a, b [3][2]*big.Int) [3][2]*big.Int {
return g2.Add(a, g2.Neg(b))
}
func (g2 G2) Double(p [3][2]*big.Int) [3][2]*big.Int {
// https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates
// http://hyperelliptic.org/EFD/g2p/auto-code/shortw/jacobian-0/doubling/dbl-2009-l.op3
// https://github.com/zcash/zcash/blob/master/src/snark/libsnark/algebra/curves/alt_bn128/alt_bn128_g2.cpp#L325
if g2.IsZero(p) {
return p
}
a := g2.F.Square(p[0])
b := g2.F.Square(p[1])
c := g2.F.Square(b)
t0 := g2.F.Add(p[0], b)
t1 := g2.F.Square(t0)
t2 := g2.F.Sub(t1, a)
t3 := g2.F.Sub(t2, c)
d := g2.F.Double(t3)
e := g2.F.Add(g2.F.Add(a, a), a)
f := g2.F.Square(e)
t4 := g2.F.Double(d)
x3 := g2.F.Sub(f, t4)
t5 := g2.F.Sub(d, x3)
twoC := g2.F.Add(c, c)
fourC := g2.F.Add(twoC, twoC)
t6 := g2.F.Add(fourC, fourC)
t7 := g2.F.Mul(e, t5)
y3 := g2.F.Sub(t7, t6)
t8 := g2.F.Mul(p[1], p[2])
z3 := g2.F.Double(t8)
return [3][2]*big.Int{x3, y3, z3}
}
func (g2 G2) MulScalar(p [3][2]*big.Int, e *big.Int) [3][2]*big.Int {
// https://en.wikipedia.org/wiki/Elliptic_curve_point_multiplication#Double-and-add
q := [3][2]*big.Int{g2.F.Zero(), g2.F.Zero(), g2.F.Zero()}
d := g2.F.F.Copy(e) // d := e
r := p
/*
here are three possible implementations:
*/
/* index decreasing: */
for i := d.BitLen() - 1; i >= 0; i-- {
q = g2.Double(q)
if d.Bit(i) == 1 {
q = g2.Add(q, r)
}
}
/* index increasing: */
// for i := 0; i <= d.BitLen(); i++ {
// if d.Bit(i) == 1 {
// q = g2.Add(q, r)
// }
// r = g2.Double(r)
// }
// foundone := false
// for i := d.BitLen(); i >= 0; i-- {
// if foundone {
// q = g2.Double(q)
// }
// if d.Bit(i) == 1 {
// foundone = true
// q = g2.Add(q, r)
// }
// }
return q
}
func (g2 G2) Affine(p [3][2]*big.Int) [3][2]*big.Int {
if g2.IsZero(p) {
return g2.Zero()
}
zinv := g2.F.Inverse(p[2])
zinv2 := g2.F.Square(zinv)
x := g2.F.Mul(p[0], zinv2)
zinv3 := g2.F.Mul(zinv2, zinv)
y := g2.F.Mul(p[1], zinv3)
return [3][2]*big.Int{
g2.F.Affine(x),
g2.F.Affine(y),
g2.F.One(),
}
}
func (g2 G2) Equal(p1, p2 [3][2]*big.Int) bool {
if g2.IsZero(p1) {
return g2.IsZero(p2)
}
if g2.IsZero(p2) {
return g2.IsZero(p1)
}
z1z1 := g2.F.Square(p1[2])
z2z2 := g2.F.Square(p2[2])
u1 := g2.F.Mul(p1[0], z2z2)
u2 := g2.F.Mul(p2[0], z1z1)
z1cub := g2.F.Mul(p1[2], z1z1)
z2cub := g2.F.Mul(p2[2], z2z2)
s1 := g2.F.Mul(p1[1], z2cub)
s2 := g2.F.Mul(p2[1], z1cub)
return g2.F.Equal(u1, u2) && g2.F.Equal(s1, s2)
}

+ 24
- 0
bn128/g2_test.go

@ -0,0 +1,24 @@
package bn128
import (
"math/big"
"testing"
"github.com/stretchr/testify/assert"
)
func TestG2(t *testing.T) {
bn128, err := NewBn128()
assert.Nil(t, err)
r1 := big.NewInt(int64(33))
r2 := big.NewInt(int64(44))
gr1 := bn128.G2.Affine(bn128.G2.MulScalar(bn128.G2.G, r1))
gr2 := bn128.G2.Affine(bn128.G2.MulScalar(bn128.G2.G, r2))
grsum1 := bn128.G2.Affine(bn128.G2.Add(gr1, gr2))
r1r2 := bn128.Fq1.Affine(bn128.Fq1.Add(r1, r2))
grsum2 := bn128.G2.Affine(bn128.G2.MulScalar(bn128.G2.G, r1r2))
assert.True(t, bn128.G2.Equal(grsum1, grsum2))
}

+ 6
- 0
go.mod

@ -0,0 +1,6 @@
module github.com/arnaucube/go-snark
require (
github.com/arnaucube/cryptofun v0.0.0-20181124004321-9b11ae8280bd
github.com/stretchr/testify v1.2.2
)

+ 8
- 0
go.sum

@ -0,0 +1,8 @@
github.com/arnaucube/cryptofun v0.0.0-20181124004321-9b11ae8280bd h1:NDpNBTFeHNE2IHya+msmKlCzIPGzn8qN3Z2jtegFYT0=
github.com/arnaucube/cryptofun v0.0.0-20181124004321-9b11ae8280bd/go.mod h1:PZE8kKpHPD1UMrS3mTfAMmEEinGtijSwjxLRqRcD64A=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=

+ 145
- 0
r1csqap.go

@ -0,0 +1,145 @@
package sn
import (
"math/big"
)
func Transpose(matrix [][]*big.Float) [][]*big.Float {
var r [][]*big.Float
for i := 0; i < len(matrix[0]); i++ {
var row []*big.Float
for j := 0; j < len(matrix); j++ {
row = append(row, matrix[j][i])
}
r = append(r, row)
}
return r
}
func ArrayOfBigZeros(num int) []*big.Float {
bigZero := big.NewFloat(float64(0))
var r []*big.Float
for i := 0; i < num; i++ {
r = append(r, bigZero)
}
return r
}
func PolMul(a, b []*big.Float) []*big.Float {
r := ArrayOfBigZeros(len(a) + len(b) - 1)
for i := 0; i < len(a); i++ {
for j := 0; j < len(b); j++ {
r[i+j] = new(big.Float).Add(
r[i+j],
new(big.Float).Mul(a[i], b[j]))
}
}
return r
}
func max(a, b int) int {
if a > b {
return a
}
return b
}
func PolAdd(a, b []*big.Float) []*big.Float {
r := ArrayOfBigZeros(max(len(a), len(b)))
for i := 0; i < len(a); i++ {
r[i] = new(big.Float).Add(r[i], a[i])
}
for i := 0; i < len(b); i++ {
r[i] = new(big.Float).Add(r[i], b[i])
}
return r
}
func PolSub(a, b []*big.Float) []*big.Float {
r := ArrayOfBigZeros(max(len(a), len(b)))
for i := 0; i < len(a); i++ {
r[i] = new(big.Float).Add(r[i], a[i])
}
for i := 0; i < len(b); i++ {
bneg := new(big.Float).Mul(b[i], big.NewFloat(float64(-1)))
r[i] = new(big.Float).Add(r[i], bneg)
}
return r
}
func FloatPow(a *big.Float, e int) *big.Float {
if e == 0 {
return big.NewFloat(float64(1))
}
result := new(big.Float).Copy(a)
for i := 0; i < e-1; i++ {
result = new(big.Float).Mul(result, a)
}
return result
}
func PolEval(v []*big.Float, x *big.Float) *big.Float {
r := big.NewFloat(float64(0))
for i := 0; i < len(v); i++ {
xi := FloatPow(x, i)
elem := new(big.Float).Mul(v[i], xi)
r = new(big.Float).Add(r, elem)
}
return r
}
func NewPolZeroAt(pointPos, totalPoints int, height *big.Float) []*big.Float {
fac := 1
for i := 1; i < totalPoints+1; i++ {
if i != pointPos {
fac = fac * (pointPos - i)
}
}
facBig := big.NewFloat(float64(fac))
hf := new(big.Float).Quo(height, facBig)
r := []*big.Float{hf}
for i := 1; i < totalPoints+1; i++ {
if i != pointPos {
ineg := big.NewFloat(float64(-i))
b1 := big.NewFloat(float64(1))
r = PolMul(r, []*big.Float{ineg, b1})
}
}
return r
}
func LagrangeInterpolation(v []*big.Float) []*big.Float {
// https://en.wikipedia.org/wiki/Lagrange_polynomial
var r []*big.Float
for i := 0; i < len(v); i++ {
r = PolAdd(r, NewPolZeroAt(i+1, len(v), v[i]))
}
//
return r
}
func R1CSToQAP(a, b, c [][]*big.Float) ([][]*big.Float, [][]*big.Float, [][]*big.Float, []*big.Float) {
aT := Transpose(a)
bT := Transpose(b)
cT := Transpose(c)
var alpha [][]*big.Float
for i := 0; i < len(aT); i++ {
alpha = append(alpha, LagrangeInterpolation(aT[i]))
}
var beta [][]*big.Float
for i := 0; i < len(bT); i++ {
beta = append(beta, LagrangeInterpolation(bT[i]))
}
var gamma [][]*big.Float
for i := 0; i < len(cT); i++ {
gamma = append(gamma, LagrangeInterpolation(cT[i]))
}
z := []*big.Float{big.NewFloat(float64(1))}
for i := 1; i < len(aT[0])+1; i++ {
ineg := big.NewFloat(float64(-i))
b1 := big.NewFloat(float64(1))
z = PolMul(z, []*big.Float{ineg, b1})
}
return alpha, beta, gamma, z
}

+ 112
- 0
r1csqap_test.go

@ -0,0 +1,112 @@
package sn
import (
"fmt"
"math/big"
"testing"
"github.com/stretchr/testify/assert"
)
func TestTranspose(t *testing.T) {
b0 := big.NewFloat(float64(0))
b1 := big.NewFloat(float64(1))
bFive := big.NewFloat(float64(5))
a := [][]*big.Float{
[]*big.Float{b0, b1, b0, b0, b0, b0},
[]*big.Float{b0, b0, b0, b1, b0, b0},
[]*big.Float{b0, b1, b0, b0, b1, b0},
[]*big.Float{bFive, b0, b0, b0, b0, b1},
}
aT := Transpose(a)
assert.Equal(t, aT, [][]*big.Float{
[]*big.Float{b0, b0, b0, bFive},
[]*big.Float{b1, b0, b1, b0},
[]*big.Float{b0, b0, b0, b0},
[]*big.Float{b0, b1, b0, b0},
[]*big.Float{b0, b0, b1, b0},
[]*big.Float{b0, b0, b0, b1},
})
}
func TestPol(t *testing.T) {
b0 := big.NewFloat(float64(0))
b1 := big.NewFloat(float64(1))
// b1neg := big.NewFloat(float64(-1))
// b2 := big.NewFloat(float64(2))
b2neg := big.NewFloat(float64(-2))
b3 := big.NewFloat(float64(3))
b4 := big.NewFloat(float64(4))
b5 := big.NewFloat(float64(5))
b6 := big.NewFloat(float64(6))
b16 := big.NewFloat(float64(16))
a := []*big.Float{b1, b0, b5}
b := []*big.Float{b3, b0, b1}
// polynomial multiplication
c := PolMul(a, b)
assert.Equal(t, c, []*big.Float{b3, b0, b16, b0, b5})
// polynomial addition
c = PolAdd(a, b)
assert.Equal(t, c, []*big.Float{b4, b0, b6})
// polynomial substraction
c = PolSub(a, b)
assert.Equal(t, c, []*big.Float{b2neg, b0, b4})
// FloatPow
p := FloatPow(big.NewFloat(float64(5)), 3)
assert.Equal(t, p, big.NewFloat(float64(125)))
p = FloatPow(big.NewFloat(float64(5)), 0)
assert.Equal(t, p, big.NewFloat(float64(1)))
// NewPolZeroAt
r := NewPolZeroAt(3, 4, b4)
assert.Equal(t, PolEval(r, big.NewFloat(3)), b4)
r = NewPolZeroAt(2, 4, b3)
assert.Equal(t, PolEval(r, big.NewFloat(2)), b3)
}
func TestLagrangeInterpolation(t *testing.T) {
b0 := big.NewFloat(float64(0))
b5 := big.NewFloat(float64(5))
a := []*big.Float{b0, b0, b0, b5}
alpha := LagrangeInterpolation(a)
assert.Equal(t, PolEval(alpha, big.NewFloat(4)), b5)
aux, _ := PolEval(alpha, big.NewFloat(3)).Int64()
assert.Equal(t, aux, int64(0))
}
func TestR1CSToQAP(t *testing.T) {
b0 := big.NewFloat(float64(0))
b1 := big.NewFloat(float64(1))
b5 := big.NewFloat(float64(5))
a := [][]*big.Float{
[]*big.Float{b0, b1, b0, b0, b0, b0},
[]*big.Float{b0, b0, b0, b1, b0, b0},
[]*big.Float{b0, b1, b0, b0, b1, b0},
[]*big.Float{b5, b0, b0, b0, b0, b1},
}
b := [][]*big.Float{
[]*big.Float{b0, b1, b0, b0, b0, b0},
[]*big.Float{b0, b1, b0, b0, b0, b0},
[]*big.Float{b1, b0, b0, b0, b0, b0},
[]*big.Float{b1, b0, b0, b0, b0, b0},
}
c := [][]*big.Float{
[]*big.Float{b0, b0, b0, b1, b0, b0},
[]*big.Float{b0, b0, b0, b0, b1, b0},
[]*big.Float{b0, b0, b0, b0, b0, b1},
[]*big.Float{b0, b0, b1, b0, b0, b0},
}
alpha, beta, gamma, z := R1CSToQAP(a, b, c)
fmt.Println(alpha)
fmt.Println(beta)
fmt.Println(gamma)
fmt.Println(z)
}

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