1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
package nizk
import (
"log"
"math/rand"
"slices"
"strings"
"sync"
"sync/atomic"
"testing"
. "kesim.org/seal/common"
)
type stage int
const (
stage1 stage = iota
stage2
)
func (s stage) String() string {
if s == stage1 {
return "stage1"
}
return "stage2"
}
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)
max2 := slices.Max(slices.Delete(slices.Clone(vals), max_idx, max_idx+1))
if max == max2 {
max_idx = -1
}
tb.Logf("running vickrey for vals:\n%0[1]*[2]b\nmax: %0[1]*[3]b, max2: %0[1]*[4]b, winner: %d\n", bitlength, vals, max, max2, max_idx)
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)
stage := stage1
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()
found := false
for k := range n {
if k == winner {
continue
}
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")
found = true
}
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")
found = true
}
}
// tb.Logf("testing max_idx %d, i %d, bit %d:\n%v vs %v", max_idx, i, idx, x, z)
return found
}
for idx := range bitlength {
for i := range n {
if i == winner {
c[i] = nil
bj[i] = nil
Xs[i] = Id
Zs[i] = Id
continue
}
c[i] = bits[i][idx].StageCommit()
Xs[i] = c[i].X
if stage == stage2 {
bj[i] = bits[i][junction]
}
}
var wg sync.WaitGroup
wg.Add(n)
fail := &atomic.Bool{}
for i := range n {
if i == winner {
tb.Logf("%s, idx: %d, skipping winner %d", stage, idx, winner)
wg.Done()
continue
}
go func(i int) {
defer wg.Done()
if stage == stage1 {
r[i], p1[i] = bits[i][idx].RevealStage1(Xs...)
if !bits[i][idx].Commitment.VerifyStage1(c[i], r[i], p1[i]) {
fail.Store(true)
tb.Fatalf("bits[i: %d][idx: %d] commitment failed to verify in stage1", i, idx)
}
} else {
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]) {
fail.Store(true)
tb.Fatalf("bits[i: %d][idx: %d] (junction: %d) verify failed in stage2, lost: %t, result so far: %05b\nXs: %v", i, idx, junction, lost[i], result, Xs)
}
}
Zs[i] = r[i].Z
}(i)
}
wg.Wait()
if fail.Load() {
tb.Fail()
return
}
Z := Curve.Product(Zs...)
tb.Logf("Z[idx: %d]: %v", idx, Z)
reset := false
if !Id.Equal(Z) {
var lost_round = make([]bool, n)
for i := range n {
if i == winner {
continue
}
if !lost[i] && !bits[i][idx].IsSet() {
lost_round[i] = true
}
// Winner test
if winner < 0 && !lost_round[i] && !lost[i] {
reset = isWinner(Z, i, idx)
if reset {
tb.Logf("found winner %d %s, idx %d", i, stage, idx)
winner = i
// stage = stage1
break
}
}
}
if !reset {
result |= 1 << (bitlength - 1 - idx)
junction = idx
stage = stage2
for i := range n {
lost[i] = lost[i] || lost_round[i]
}
}
}
tb.Logf("lost: %t, result: %08b", lost, result)
}
if result != max2 {
tb.Fatalf("wrong result: %0[1]*[2]b, exp. max2: %0[1]*[3]b, max: %0[1]*[4]b\nvals: %0[1]*[5]b", bitlength, result, max2, max, vals)
}
if max_idx != winner {
tb.Fatalf("wrong winner, max_idx: %d vs winner: %d val %08b\nvals: %08b", max_idx, winner, max2, vals)
}
}
func TestAuction4on6bit(t *testing.T) { runSeal(4, 6, t) }
// func TestAuction100on24bit(t *testing.T) { runSeal(100, 24, t) }
func TestVickrey4on6bit(t *testing.T) { runVickrey(4, 6, t) }
func TestVickrey100on16bit(t *testing.T) { runVickrey(100, 16, t) }
func BenchmarkVickrey100on24bit(b *testing.B) {
for range b.N {
runVickrey(100, 24, b)
}
}
|
