forked from liyue201/gnark-circomlib
/
pedersen.go
168 lines (141 loc) · 5.77 KB
/
pedersen.go
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package circuits
import (
"github.com/consensys/gnark/frontend"
"math/big"
)
func Window4(api frontend.API, in []frontend.Variable, base []frontend.Variable) ([]frontend.Variable, []frontend.Variable) {
if len(in) != 4 || len(base) != 2 {
panic("invalid param")
}
out := make([]frontend.Variable, 2)
out8 := make([]frontend.Variable, 2)
c := Make2DVariableArray(2, 8)
// in[0] -> 1*BASE
c[0][0] = base[0]
c[1][0] = base[1]
// in[1] -> 2*BASE
dbl2 := MontgomeryDouble(api, base[:2])
c[0][1] = dbl2[0]
c[1][1] = dbl2[1]
// in[2] -> 3*BASE
adr3 := MontgomeryAdd(api, base[:2], dbl2[:2])
c[0][2] = adr3[0]
c[1][2] = adr3[1]
// in[3] -> 4*BASE
adr4 := MontgomeryAdd(api, base[:2], adr3[:2])
c[0][3] = adr4[0]
c[1][3] = adr4[1]
// in[4] -> 5*BASE
adr5 := MontgomeryAdd(api, base[:2], adr4[:2])
c[0][4] = adr5[0]
c[1][4] = adr5[1]
// in[5] -> 6*BASE
adr6 := MontgomeryAdd(api, base[:2], adr5[:2])
c[0][5] = adr6[0]
c[1][5] = adr6[1]
// in[6] -> 7*BASE
adr7 := MontgomeryAdd(api, base[:2], adr6[:2])
c[0][6] = adr7[0]
c[1][6] = adr7[1]
// in[7] -> 8*BASE
adr8 := MontgomeryAdd(api, base[:2], adr7[:2])
c[0][7] = adr8[0]
c[1][7] = adr8[1]
out8 = adr8
mux := MultiMux3(api, c, in[:3])
out[0] = mux[0]
out[1] = api.Sub(mux[1], api.Mul(mux[1], 2, in[3]))
return out, out8
}
func Segment(api frontend.API, in []frontend.Variable, base []frontend.Variable) []frontend.Variable {
if len(base) != 2 {
panic("invalid param")
}
nWindows := len(in) / 4
out := make([]frontend.Variable, 2)
e2m := Edwards2Montgomery(api, base)
windowsOut := MakeVariableArray(2)
windowsOut8 := MakeVariableArray(2)
adders := MakeVariableArray(2)
for i := 0; i < nWindows; i++ {
windowsIn := MakeVariableArray(4)
for j := 0; j < 4; j++ {
windowsIn[j] = in[i*4+j]
}
if i == 0 {
windowsOut, windowsOut8 = Window4(api, windowsIn, e2m)
} else {
doublers1 := MontgomeryDouble(api, windowsOut8)
doublers2 := MontgomeryDouble(api, doublers1)
thisWindowsOut, thisWindowsOut8 := Window4(api, windowsIn, doublers2)
if i == 1 {
adders = MontgomeryAdd(api, windowsOut, thisWindowsOut)
} else {
adders = MontgomeryAdd(api, adders, thisWindowsOut)
}
windowsOut = thisWindowsOut
windowsOut8 = thisWindowsOut8
}
}
if nWindows > 1 {
out = Montgomery2Edwards(api, adders)
} else {
out = Montgomery2Edwards(api, windowsOut)
}
return out
}
func Pedersen(api frontend.API, in []frontend.Variable) []frontend.Variable {
var BASE [10][2]*big.Int
BASE[0][0], _ = new(big.Int).SetString("10457101036533406547632367118273992217979173478358440826365724437999023779287", 10)
BASE[0][1], _ = new(big.Int).SetString("19824078218392094440610104313265183977899662750282163392862422243483260492317", 10)
BASE[1][0], _ = new(big.Int).SetString("2671756056509184035029146175565761955751135805354291559563293617232983272177", 10)
BASE[1][1], _ = new(big.Int).SetString("2663205510731142763556352975002641716101654201788071096152948830924149045094", 10)
BASE[2][0], _ = new(big.Int).SetString("5802099305472655231388284418920769829666717045250560929368476121199858275951", 10)
BASE[2][1], _ = new(big.Int).SetString("5980429700218124965372158798884772646841287887664001482443826541541529227896", 10)
BASE[3][0], _ = new(big.Int).SetString("7107336197374528537877327281242680114152313102022415488494307685842428166594", 10)
BASE[3][1], _ = new(big.Int).SetString("2857869773864086953506483169737724679646433914307247183624878062391496185654", 10)
BASE[4][0], _ = new(big.Int).SetString("20265828622013100949498132415626198973119240347465898028410217039057588424236", 10)
BASE[4][1], _ = new(big.Int).SetString("1160461593266035632937973507065134938065359936056410650153315956301179689506", 10)
BASE[5][0], _ = new(big.Int).SetString("1487999857809287756929114517587739322941449154962237464737694709326309567994", 10)
BASE[5][1], _ = new(big.Int).SetString("14017256862867289575056460215526364897734808720610101650676790868051368668003", 10)
BASE[6][0], _ = new(big.Int).SetString("14618644331049802168996997831720384953259095788558646464435263343433563860015", 10)
BASE[6][1], _ = new(big.Int).SetString("13115243279999696210147231297848654998887864576952244320558158620692603342236", 10)
BASE[7][0], _ = new(big.Int).SetString("6814338563135591367010655964669793483652536871717891893032616415581401894627", 10)
BASE[7][1], _ = new(big.Int).SetString("13660303521961041205824633772157003587453809761793065294055279768121314853695", 10)
BASE[8][0], _ = new(big.Int).SetString("3571615583211663069428808372184817973703476260057504149923239576077102575715", 10)
BASE[8][1], _ = new(big.Int).SetString("11981351099832644138306422070127357074117642951423551606012551622164230222506", 10)
BASE[9][0], _ = new(big.Int).SetString("18597552580465440374022635246985743886550544261632147935254624835147509493269", 10)
BASE[9][1], _ = new(big.Int).SetString("6753322320275422086923032033899357299485124665258735666995435957890214041481", 10)
n := len(in)
nSegments := (n + 199) / 200
segments := Make2DVariableArray(nSegments, 2)
for i := 0; i < nSegments; i++ {
nBits := 200
if i == nSegments-1 {
nBits = n - (nSegments-1)*200
}
nWindows := (nBits + 3) / 4
segmentsIn := MakeVariableArray(nWindows * 4)
for j := 0; j < nBits; j++ {
segmentsIn[j] = in[i*200+j]
}
segments[i] = Segment(api, segmentsIn, []frontend.Variable{BASE[i][0], BASE[i][1]})
}
var adderX, adderY frontend.Variable
for i := 0; i < nSegments-1; i++ {
if i == 0 {
adderX, adderY = BabyAdd(api, segments[0][0], segments[0][1], segments[1][0], segments[1][1])
} else {
adderX, adderY = BabyAdd(api, adderX, adderY, segments[i+1][0], segments[i+1][1])
}
}
out := MakeVariableArray(2)
if nSegments > 1 {
out[0] = adderX
out[1] = adderY
} else {
out[0] = segments[0][0]
out[1] = segments[0][1]
}
return out
}