Set-Membership Zero-Knowledge Proofs

So, let’s say there’s a number of winning tickets in a lottery of [654, 703, 991, 1011], can I prove I have a value which is in this set, and without giving away the number on my ticket? Well, one of my favouriate researchers — Jan Camenisch — created a method where we can prove that we have a value in a set of values, and without giving our value away [1][here]:

The paper was produced in 2008, and is often referred to as CSS08. With this, we provide a zero-knowledge proof that σ is included in a discrete set
Φ. This set is represented as 64-bit integers, and could thus be hashed version of string.

The code used is [here]:

package main

import (
 "crypto/rand"
 "fmt"
 "os"

 "strconv"
 "strings"

 "github.com/ing-bank/zkrp/ccs08"
 "go.dedis.ch/kyber/v3/pairing/bn256"
)

func StringToIntArray(A string) []int64 {
 strs := strings.Split(A, " ")
 ary := make([]int64, len(strs))
 for i := range ary {
  v, _ := strconv.Atoi(strs[i])
  ary[i] = int64(v)
 }
 return ary
}

func main() {

 tofind := 6
 set := "1 2 3 4 5"

 argCount := len(os.Args[1:])

 if argCount > 0 {
  tofind, _ = strconv.Atoi(os.Args[1])
 }
 if argCount > 1 {
  set =…