-rw-r--r-- 2942 cryptattacktester-20230614/uniformmatrix.cpp raw
#include <vector>
#include "bigint.h"
#include "random.h"
#include "selection.h"
#include "decoding.h"
#include "uniformmatrix.h"

using namespace std;

std::vector<const char *> uniformmatrix_paramnames = {"N","K","W"};

vector<vector<bigint>> uniformmatrix_params(map<string,string> &S)
{
  vector<vector<bigint>> result;

  bigint Nmin = 8;
  bigint Nmax = 8192;
  selection_constrain(S,"N",Nmin,Nmax);
  for (bigint N = Nmin;N <= Nmax;++N) {
    if (N < 8) continue;
    if (Nmin != Nmax) if (N%16 != 0) continue;

    bigint lgq = 1;
    bigint q = 2;
    while (q < N) { ++lgq; q *= 2; }

    bigint Wmin = 0;
    bigint Wmax = N;
    selection_constrain(S,"W",Wmin,Wmax);
    for (bigint W = Wmin;W <= Wmax;++W) {
      bigint K = N-lgq*W;
      if (10*K < 7*N) break;
      if (10*K > 8*N) continue;
      if (!selection_allows(S,"K",K.get_str())) continue;

      result.push_back(vector<bigint> {N,K,W});
    }
  }

  return result;
}

bigint uniformmatrix_numinputs(const vector<bigint> &params)
{
  bigint n = params.at(0);
  bigint k = params.at(1);
  bigint w = params.at(2);
  return binomial(n,w);
}

bigint uniformmatrix_numoutputs(const vector<bigint> &params)
{
  bigint n = params.at(0);
  bigint k = params.at(1);
  bigint w = params.at(2);
  bigint result = 1;
  result <<= n-k;
  return result;
}

vector<vector<bool>> uniformmatrix_publickey(const vector<bigint> &params)
{
  bigint n = params.at(0);
  bigint k = params.at(1);
  vector<vector<bool>> result;

  for (bigint i = 0;i < n-k;++i) {
    vector<bool> resulti;
    for (bigint j = 0;j < k;++j)
      resulti.push_back(random_bool());
    result.push_back(resulti);
  }
  return result;
}

vector<bool> uniformmatrix_plaintext(const vector<bigint> &params)
{
  bigint n = params.at(0);
  bigint w = params.at(2);
  vector<bool> result(n);

  bigint q = 1;
  while (q < n) q *= 2;

  while (w > 0) {
    bigint pos = random_bigint_below(q);
    if (pos < n)
      if (result.at(pos) == 0) {
        result.at(pos) = 1;
        --w;
      }
  }
  return result;
}

vector<bool> uniformmatrix_enc(const vector<bigint> &params,const vector<bool> &m,const vector<vector<bool>> &pk)
{
  bigint n = params.at(0);
  bigint k = params.at(1);

  vector<vector<bool>> H;
  for (bigint i = 0;i < n-k;++i) {
    vector<bool> Hi;
    for (bigint j = 0;j < n-k;++j)
      Hi.push_back(i == j);
    Hi.insert(Hi.end(),pk.at(i).begin(),pk.at(i).end());
    H.push_back(Hi);
  }

  vector<bool> result;
  for (bigint i = 0;i < n-k;++i) {
    bool resulti = 0;
    for (bigint j = 0;j < n;++j)
      resulti ^= H.at(i).at(j) & m.at(j);
    result.push_back(resulti);
  }
  return result;
}

pair<vector<bool>,vector<bool>> uniformmatrix(const vector<bigint> &params)
{
  auto pk = uniformmatrix_publickey(params);
  auto m = uniformmatrix_plaintext(params);
  auto ct = uniformmatrix_enc(params,m,pk);
  auto pub = decoding_serialize(pk,ct,params);
  return make_pair(pub,m);
}