@ -1,8 +1,7 @@
package z k
package snar k
import (
"crypto/rand"
"fmt"
"math/big"
"github.com/arnaucube/go-snark/bn128"
@ -11,16 +10,25 @@ import (
type Setup struct {
Toxic struct {
T * big . Int // trusted setup secret
Ka * big . Int // prover
Kb * big . Int // prover
Kc * big . Int // prover
T * big . Int // trusted setup secret
Ka * big . Int // prover
Kb * big . Int // prover
Kc * big . Int // prover
Kbeta * big . Int
Kgamma * big . Int
RhoA * big . Int
RhoB * big . Int
RhoC * big . Int
}
// public
G1T [ ] [ 3 ] * big . Int // t encrypted in G1 curve
G2T [ ] [ 3 ] [ 2 ] * big . Int // t encrypted in G2 curve
G1T [ ] [ 3 ] * big . Int // t encrypted in G1 curve
G2T [ ] [ 3 ] [ 2 ] * big . Int // t encrypted in G2 curve
G1Kbg [ 3 ] * big . Int // g1 * Kbeta * Kgamma
G2Kbg [ 3 ] [ 2 ] * big . Int // g2 * Kbeta * Kgamma
G2Kg [ 3 ] [ 2 ] * big . Int // g2 * Kgamma
}
type Proof struct {
PiA [ 3 ] * big . Int
PiAp [ 3 ] * big . Int
@ -29,6 +37,7 @@ type Proof struct {
PiC [ 3 ] * big . Int
PiCp [ 3 ] * big . Int
PiH [ 3 ] * big . Int
PiK [ 3 ] * big . Int
Va [ 3 ] [ 2 ] * big . Int
Vb [ 3 ] * big . Int
Vc [ 3 ] [ 2 ] * big . Int
@ -37,7 +46,7 @@ type Proof struct {
const bits = 512
func GenerateTrustedSetup ( bn bn128 . Bn128 , poll ength int ) ( Setup , error ) {
func GenerateTrustedSetup ( bn bn128 . Bn128 , polL ength int ) ( Setup , error ) {
var setup Setup
var err error
// generate random t value
@ -45,13 +54,46 @@ func GenerateTrustedSetup(bn bn128.Bn128, pollength int) (Setup, error) {
if err != nil {
return Setup { } , err
}
fmt . Print ( "trusted t: " )
fmt . Println ( setup . Toxic . T )
// k for calculating pi' and Vk
setup . Toxic . Ka , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Setup { } , err
}
setup . Toxic . Kb , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Setup { } , err
}
setup . Toxic . Kc , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Setup { } , err
}
// generate Kβ (Kbeta) and Kγ (Kgamma)
setup . Toxic . Kbeta , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Setup { } , err
}
setup . Toxic . Kgamma , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Setup { } , err
}
// generate ρ (Rho): ρA, ρB, ρC
setup . Toxic . RhoA , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Setup { } , err
}
setup . Toxic . RhoB , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Setup { } , err
}
setup . Toxic . RhoC = bn . Fq1 . Mul ( setup . Toxic . RhoA , setup . Toxic . RhoB )
// encrypt t values with curve generators
var gt1 [ ] [ 3 ] * big . Int
var gt2 [ ] [ 3 ] [ 2 ] * big . Int
for i := 0 ; i < pollength ; i ++ {
for i := 0 ; i < polL ength ; i ++ {
tPow := bn . Fq1 . Exp ( setup . Toxic . T , big . NewInt ( int64 ( i ) ) )
tEncr1 := bn . G1 . MulScalar ( bn . G1 . G , tPow )
gt1 = append ( gt1 , tEncr1 )
@ -63,26 +105,22 @@ func GenerateTrustedSetup(bn bn128.Bn128, pollength int) (Setup, error) {
setup . G1T = gt1
setup . G2T = gt2
/ *
Verification keys :
- Vk_betagamma1 : setup . G1Kbg = g1 * Kbeta * Kgamma
- Vk_betagamma2 : setup . G2Kbg = g2 * Kbeta * Kgamma
- Vk_gamma : setup . G2Kg = g2 * Kgamma
* /
kbg := bn . Fq1 . Mul ( setup . Toxic . Kbeta , setup . Toxic . Kgamma )
setup . G1Kbg = bn . G1 . MulScalar ( bn . G1 . G , kbg )
setup . G2Kbg = bn . G2 . MulScalar ( bn . G2 . G , kbg )
setup . G2Kg = bn . G2 . MulScalar ( bn . G2 . G , setup . Toxic . Kgamma )
return setup , nil
}
func GenerateProofs ( bn bn128 . Bn128 , f fields . Fq , setup Setup , ax , bx , cx , hx , zx [ ] * big . Int ) ( Proof , error ) {
func GenerateProofs ( bn bn128 . Bn128 , f fields . Fq , setup Setup , w , ax , bx , cx , hx , zx [ ] * big . Int ) ( Proof , error ) {
var proof Proof
var err error
// k for calculating pi' and Vk
setup . Toxic . Ka , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Proof { } , err
}
setup . Toxic . Kb , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Proof { } , err
}
setup . Toxic . Kc , err = rand . Prime ( rand . Reader , bits )
if err != nil {
return Proof { } , err
}
// g1*A(t)
proof . PiA = [ 3 ] * big . Int { bn . G1 . F . Zero ( ) , bn . G1 . F . Zero ( ) , bn . G1 . F . Zero ( ) }
@ -90,7 +128,7 @@ func GenerateProofs(bn bn128.Bn128, f fields.Fq, setup Setup, ax, bx, cx, hx, zx
m := bn . G1 . MulScalar ( setup . G1T [ i ] , ax [ i ] )
proof . PiA = bn . G1 . Add ( proof . PiA , m )
}
proof . PiAp = bn . G1 . MulScalar ( proof . PiA , setup . Toxic . Ka )
proof . PiAp = bn . G1 . MulScalar ( proof . PiA , setup . Toxic . Ka ) // move this in the setup step
// g2*B(t)
proof . PiB = bn . Fq6 . Zero ( )
@ -102,7 +140,7 @@ func GenerateProofs(bn bn128.Bn128, f fields.Fq, setup Setup, ax, bx, cx, hx, zx
m1 := bn . G1 . MulScalar ( setup . G1T [ i ] , bx [ i ] )
pib1 = bn . G1 . Add ( pib1 , m1 )
}
proof . PiBp = bn . G1 . MulScalar ( pib1 , setup . Toxic . Kb )
proof . PiBp = bn . G1 . MulScalar ( pib1 , setup . Toxic . Kb ) // this in the setup step
// g1*C(t)
proof . PiC = [ 3 ] * big . Int { bn . G1 . F . Zero ( ) , bn . G1 . F . Zero ( ) , bn . G1 . F . Zero ( ) }
@ -110,7 +148,7 @@ func GenerateProofs(bn bn128.Bn128, f fields.Fq, setup Setup, ax, bx, cx, hx, zx
m := bn . G1 . MulScalar ( setup . G1T [ i ] , cx [ i ] )
proof . PiC = bn . G1 . Add ( proof . PiC , m )
}
proof . PiCp = bn . G1 . MulScalar ( proof . PiC , setup . Toxic . Kc )
proof . PiCp = bn . G1 . MulScalar ( proof . PiC , setup . Toxic . Kc ) // this in the setup step
// g1*H(t)
proof . PiH = [ 3 ] * big . Int { bn . G1 . F . Zero ( ) , bn . G1 . F . Zero ( ) , bn . G1 . F . Zero ( ) }
@ -119,15 +157,17 @@ func GenerateProofs(bn bn128.Bn128, f fields.Fq, setup Setup, ax, bx, cx, hx, zx
proof . PiH = bn . G1 . Add ( proof . PiH , m )
}
g2Zt : = bn . Fq6 . Zero ( )
proof . Vz = bn . Fq6 . Zero ( )
for i := 0 ; i < len ( bx ) ; i ++ {
m := bn . G2 . MulScalar ( setup . G2T [ i ] , zx [ i ] )
g2Zt = bn . G2 . Add ( g2Zt , m )
proof . Vz = bn . G2 . Add ( proof . Vz , m )
}
proof . Vz = g2Zt
proof . Va = bn . G2 . MulScalar ( bn . G2 . G , setup . Toxic . Ka )
proof . Vb = bn . G1 . MulScalar ( bn . G1 . G , setup . Toxic . Kb )
proof . Vc = bn . G2 . MulScalar ( bn . G2 . G , setup . Toxic . Kc )
// proof.Vz = g2Zt
proof . Va = bn . G2 . MulScalar ( bn . G2 . G , setup . Toxic . Ka ) // this in the setup step
proof . Vb = bn . G1 . MulScalar ( bn . G1 . G , setup . Toxic . Kb ) // this in the setup step
proof . Vc = bn . G2 . MulScalar ( bn . G2 . G , setup . Toxic . Kc ) // this in the setup step
return proof , nil
}
@ -173,21 +213,36 @@ func VerifyProof(bn bn128.Bn128, setup Setup, proof Proof) bool {
return false
}
// e(piA+piC, g2KbetaKgamma) * e(g1KbetaKgamma, piB)
// == e(piK, g2Kgamma)
// piApiC := bn.G1.Add(proof.PiA, proof.PiC)
// pairingPiACG2Kbg, err := bn.Pairing(piApiC, setup.G2Kbg)
// if err != nil {
// return false
// }
// pairingG1KbgPiB, err := bn.Pairing(setup.G1Kbg, proof.PiB)
// if err != nil {
// return false
// }
// pairing1 := bn.Fq12.Mul(pairingPiACG2Kbg, pairingG1KbgPiB)
//
// e(piA, piB) == e(piH, Vz) * e(piC, g2)
// pairingPiaPib, err := bn.Pairing(proof.PiA, proof.PiB)
// if err != nil {
// return false
// return false
// }
// pairingPihVz, err := bn.Pairing(proof.PiH, proof.Vz)
// if err != nil {
// return false
// return false
// }
// pairingPicG2, err := bn.Pairing(proof.PiC, bn.G2.G)
// if err != nil {
// return false
// return false
// }
// if !bn.Fq12.Equal(pairingPiaPib, bn.Fq12.Mul(pairingPihVz, pairingPicG2)) {
// return false
// return false
// }
return true