ZZX myCRT::DecodeMessage(ZZX &mes){
ZZ t; ZZX res; ZZ_pX mess_p, tm;
mess_p = to_ZZ_pX(mes);
for(int i=0; i<size; i++){
tm = mess_p%factors[i];
t = rep(coeff(tm,0));
t=t%to_ZZ("2");
SetCoeff(res, i, t);
}
return res;
}
void myCRT::ComputeFactors(int f_degree, int f_size){
factors.SetLength(f_size);
int s = 1<<f_degree;
ZZ_pX list[s];
for(int i=0; i<s; i++)
list[i] = to_ZZ_pX(num2ZZX(i+s));
int j=0;
ZZ_pX t1 = modulus;
ZZ_pX comp, remin, quo;
SetCoeff(comp, 0, 0);
for(int i=0; i<s; i++){
DivRem(quo, remin, t1, list[i]);
if(remin == comp){
t1 = quo;
factors[j] = list[i];
j++;
}
}
size = factors.length();
}
//Comparison protocol based on ""
bool COM(bool disp, long long seed, unsigned p, FHEcontext &context) {
ZZ seedZZ;
seedZZ = seed;
srand48(seed);
SetSeed(seedZZ);
FHESISecKey secretKey(context);
const FHESIPubKey &publicKey(secretKey);
long phim = context.zMstar.phiM();
ZZ_pX ptxt1Poly, ptxt2Poly, sum, sumMult, prod, prod2, sumQuad;
Plaintext resSum, resSumMult, resProd, resProdSwitch, resProd2, resSumQuad;
//gen plaintext
ptxt1Poly.rep.SetLength(phim);
ptxt2Poly.rep.SetLength(phim);
for (long i=0; i < phim; i++) {
ptxt1Poly.rep[i] = RandomBnd(p);
ptxt2Poly.rep[i] = RandomBnd(p);
}
//printpoly(ptxt1Poly, phim);
ptxt1Poly.normalize();
ptxt2Poly.normalize();
#ifdef DEBUG
cout<<"phim:"<<phim<<endl;
cout<<"p1:"<<endl;
printpoly(ptxt1Poly, phim);
cout<<"p2:"<<endl;
printpoly(ptxt2Poly, phim);
#endif
//plaintext operation
sum = ptxt1Poly + ptxt2Poly;
sumMult = ptxt2Poly * 7;
prod = ptxt1Poly * ptxt2Poly;
prod2 = prod * prod;
sumQuad = prod2 * prod2 * 9; //\sum_((xy)^4)
#ifdef DEBUG
cout<<"sum:"<<endl;
printpoly(sum, phim);
cout<<"prod2:"<<endl;
printpoly(prod2, phim);
#endif
rem(prod, prod, to_ZZ_pX(context.zMstar.PhimX()));
rem(prod2, prod2, to_ZZ_pX(context.zMstar.PhimX()));
rem(sumQuad, sumQuad, to_ZZ_pX(context.zMstar.PhimX()));
//encryption
start = std::clock();
Plaintext ptxt1(context, ptxt1Poly), ptxt2(context, ptxt2Poly);
duration = ( std::clock() - start ) / (double) CLOCKS_PER_SEC;
duration = duration/2;
cout<<"Encryption:"<< duration <<'\n';
Ciphertext ctxt1(publicKey), ctxt2(publicKey);
publicKey.Encrypt(ctxt1, ptxt1);
publicKey.Encrypt(ctxt2, ptxt2);
Ciphertext cSum = ctxt1;
cSum += ctxt2;
Ciphertext cSumMult = ctxt2;
start = std::clock();
for (int i = 1; i < 7; i++) {
cSumMult += ctxt2;
}
duration = ( std::clock() - start ) / (double) (CLOCKS_PER_SEC);
duration = duration/6;
cout<<"Addition:"<< duration <<'\n';
Ciphertext cProd = ctxt1;
cProd *= ctxt2;
secretKey.Decrypt(resSum, cSum);
secretKey.Decrypt(resSumMult, cSumMult);
KeySwitchSI keySwitch(secretKey);
keySwitch.ApplyKeySwitch(cProd);
secretKey.Decrypt(resProd, cProd);
cProd *= cProd;
Ciphertext tmp = cProd;
Ciphertext cSumQuad = cProd;
keySwitch.ApplyKeySwitch(cProd);
secretKey.Decrypt(resProd2, cProd);
for (int i = 0; i < 8; i++) {
cSumQuad += tmp;
}
keySwitch.ApplyKeySwitch(cSumQuad); //apply key switch after summing all prod
start = std::clock();
cSumQuad *= cProd;
duration = ( std::clock() - start ) / (double) (CLOCKS_PER_SEC);
cout<<"HMult without key switch:"<< duration <<'\n';
keySwitch.ApplyKeySwitch(cSumQuad);
duration = ( std::clock() - start ) / (double) (CLOCKS_PER_SEC);
cout<<"HMult with key switch:"<< duration <<'\n';
start = std::clock();
secretKey.Decrypt(resSumQuad, cSumQuad);
duration = ( std::clock() - start ) / (double) (CLOCKS_PER_SEC);
cout<<"Decryption:"<< duration <<'\n';
//comparison
bool success = ((resSum.message == sum) && (resSumMult.message == sumMult) &&
(resProd.message == prod) && (resProd2.message == prod2) &&
(resSumQuad == sumQuad));
if (disp || !success) {
cout << "Seed: " << seed << endl << endl;
if (resSum.message != sum) {
cout << "Add failed." << endl;
}
if (resSumMult.message != sumMult) {
cout << "Adding multiple times failed." << endl;
}
if (resProd.message != prod) {
cout << "Multiply failed." << endl;
}
if (resProd2.message != prod2) {
cout << "Squaring failed." << endl;
}
if (resSumQuad.message != sumQuad) {
cout << "Sum and quad failed." << endl;
}
}
if (disp || !success) {
cout << "Test " << (success ? "SUCCEEDED" : "FAILED") << endl;
}
return success;
}
void myCRT::SetModulus(ZZX &m){
modulus = to_ZZ_pX(m);
}
