Re: Pollard's kangaroo ECDLP solver

Hi, i'm having some issues saving the private key once found, it does not get saved?

It does not save. Are you compiling your own version? If so, I can give you a code snippet to add to source file that will generate a saved file with pub and priv key.

No i'm just using the release version, ah that's a little concerning, would be nice to save in case of a power outage, crash or accidental cmd close.

It looks something like this:
in Kangaroo.cpp

Code:

bool Kangaroo::output(string msg) {

FILE *f = stdout;
f = fopen("Result.txt", "a");

if (f == NULL) {
printf("[error] Cannot open file Result.txt for writing! \n");
f = stdout;
return false;
}
else {
fprintf(f, "%s\n", msg.c_str());
fclose(f);
printf("[i] Success saved to file Result.txt\n");
return true;
}
}

and

Code:

bool Kangaroo::CheckKey(Int d1,Int d2,uint8_t type) {

// Resolve equivalence collision

if(type & 0x1)
d1.ModNegK1order();
if(type & 0x2)
d2.ModNegK1order();

Int pk(&d1);
pk.ModAddK1order(&d2);

Point P = secp->ComputePublicKey(&pk);

if(P.equals(keyToSearch)) {
// Key solved
#ifdef USE_SYMMETRY
pk.ModAddK1order(&rangeWidthDiv2);
#endif
pk.ModAddK1order(&rangeStart);
Point PR = secp->ComputePublicKey(&pk);
::printf("\nKey#%2d [%dN]Pub: 0x%s \n",keyIdx,type,secp->GetPublicKeyHex(true,keysToSearch[keyIdx]).c_str());
// Save Priv
std::string prvkey = pk.GetBase16().c_str();
bool save_pk = output(prvkey + string(":") + string("04") + PR.x.GetBase16().c_str() + PR.y.GetBase16().c_str() );
if( PR.equals(keysToSearch[keyIdx]) ) {
::printf(" Priv: 0x%s \n",pk.GetBase16().c_str());
} else {
::printf(" Failed !\n");
::printf(" Priv: 0x%s \n",pk.GetBase16().c_str());
return false;
}
return true;
}

if(P.equals(keyToSearchNeg)) {
// Key solved
pk.ModNegK1order();
#ifdef USE_SYMMETRY
pk.ModAddK1order(&rangeWidthDiv2);
#endif
pk.ModAddK1order(&rangeStart);
Point PR = secp->ComputePublicKey(&pk);
::printf("\nKey#%2d [%dS]Pub: 0x%s \n",keyIdx,type,secp->GetPublicKeyHex(true,keysToSearch[keyIdx]).c_str());
// Save Priv
std::string prvkeyNeg = pk.GetBase16().c_str();
bool save_pk = output(prvkeyNeg + string(":") + string("04") + PR.x.GetBase16().c_str() + PR.y.GetBase16().c_str() );
if(PR.equals(keysToSearch[keyIdx]) ) {
::printf(" Priv: 0x%s \n",pk.GetBase16().c_str());
} else {
::printf(" Failed !\n");
::printf(" Priv: 0x%s \n",pk.GetBase16().c_str());
return false;
}
return true;
}

return false;

}

Add in Kangaroo.h

Code:

bool output(std::string msg);

But I do not need this, I use my version. Where the problem with RAM is solved, can change the number of files to save DP. But the problems with disk space have begun

GPU #0 Tesla P100-PCIE-16GB (56x64 cores) Grid(112x128) (177.0 MB used; GRP size: 128)

Maybe it will be on Github.