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|
package nizk
import (
"log"
"math/rand"
"slices"
"strings"
"sync"
"testing"
. "kesim.org/seal/common"
)
func runVickrey(n int, bitlength int, tb testing.TB) {
var vals = make([]int, n)
var ids = make([]Bytes, n)
for i := range n {
vals[i] = rand.Intn(1<<(bitlength-1) - 1)
ids[i] = Curve.RandomScalar()
}
max := slices.Max(vals)
max_idx := slices.Index(vals, max)
if max_idx < len(vals)-1 && max == slices.Max(vals[max_idx+1:]) {
max_idx = -1
}
var bits = make([][]*Bit, n)
for i, b := range vals {
bits[i] = Int2Bits(ids[i], b, bitlength)
}
var c = make([]*StageCommitment, n)
var Xs = make([]*Point, n)
var r = make([]*StageReveal, n)
var p1 = make([]*Stage1Proof, n)
var Zs = make([]*Point, n)
var bj = make([]*Bit, n)
var p2 = make([]*Stage2Proof, n)
var lost = make([]bool, n)
instage1 := true
junction := -1
winner := -1
result := 0
isWinner := func(Z *Point, i int, idx int) bool {
z := Z.Div(Zs[i])
xu := Curve.Identity()
xl := Curve.Identity()
for k := range n {
if k < i {
xu = xu.Mul(Xs[k])
} else if k > i {
xl = xl.Mul(Xs[k])
}
}
xu = xu.Exp(bits[i][idx].Stage.x)
xl = xl.Exp(bits[i][idx].Stage.x)
x := xu.Div(xl)
if x.Equal(z) {
tb.Logf("equal by value")
winner = i
}
if winner < 0 {
// BUG! TODO!
s1 := x.String()
s2 := z.String()
if strings.HasPrefix(s1, s2[:len(s2)-2]) {
log.Printf("BUG! TODO! equal only by string")
winner = i
}
}
tb.Logf("testing max_idx %d, i %d, bit %d:\n%v vs %v", max_idx, i, idx, x, z)
return winner >= 0
}
for idx := range bitlength {
for i := range n {
c[i] = bits[i][idx].StageCommit()
Xs[i] = c[i].X
}
if instage1 {
var wg sync.WaitGroup
wg.Add(n)
for i := range n {
go func() {
r[i], p1[i] = bits[i][idx].RevealStage1(Xs...)
if !bits[i][idx].Commitment.VerifyStage1(c[i], r[i], p1[i]) {
tb.Fatalf("bits[%d][%d] commitment failed to verify in stage1", i, idx)
}
Zs[i] = r[i].Z
wg.Done()
}()
}
wg.Wait()
Z := Curve.Product(Zs...)
if !Id.Equal(Z) {
junction = idx
instage1 = false
for i := range bits {
if !lost[i] && !bits[i][idx].IsSet() {
lost[i] = true
}
// Winner test
if !lost[i] {
isWinner(Z, i, idx)
}
}
result |= 1 << (bitlength - 1 - idx)
}
continue
}
// Stage 2
for i := range bits {
bj[i] = bits[i][junction]
}
var wg sync.WaitGroup
wg.Add(n)
for i := range n {
go func() {
r[i], p2[i] = bits[i][idx].RevealStage2(lost[i], bj[i], Xs...)
if !bits[i][idx].Commitment.VerifyStage2(bj[i].StageCommitment, c[i], bj[i].StageReveal, r[i], p2[i]) {
tb.Fatalf("bits[%d][%d] commitment failed to verify in stage2, result so far: %05b", i, idx, result)
}
Zs[i] = r[i].Z
wg.Done()
}()
}
wg.Wait()
Z := Curve.Product(Zs...)
if !Id.Equal(Z) {
junction = idx
for i := range n {
if !lost[i] && !bits[i][idx].IsSet() {
lost[i] = true
}
// Winner test
if !lost[i] && winner < 0 {
isWinner(Z, i, idx)
}
}
result |= 1 << (bitlength - 1 - idx)
}
}
if result != max {
tb.Fatalf("wrong result: %0[1]*[2]b, expected: %0[1]*[3]b", bitlength, result, max)
}
if max_idx != winner {
tb.Fatalf("wrong winner, max_idx: %d vs winner: %d val %08b\nvals=%08b", max_idx, winner, max, vals)
}
}
func TestVickrey100on16bit(t *testing.T) { runVickrey(100, 16, t) }
|
