private List <Tuple <PlainCipherPair32, PlainCipherPair32> > BuildGoodPair(
DifferentialCharacteristic characteristic)
{
var cipher = new OneRoundSimpleCipher.OneRoundSimpleCipher();
var result = new List <Tuple <PlainCipherPair32, PlainCipherPair32> >();
for (var i = 0; i < 16; ++i)
{
var firstPlain = i;
var firstPlainBytes = BitConverter.GetBytes(firstPlain);
Array.Reverse(firstPlainBytes);
var secondPlain = firstPlain ^ characteristic.InputDifferential;
var secondPlainBytes = BitConverter.GetBytes(secondPlain);
Array.Reverse(secondPlainBytes);
if (characteristic.InputDifferential == 4 && characteristic.OutputDifferential == 7)
{
if (i == 11)
{
Console.WriteLine($"LOL {firstPlain} {secondPlain}");
}
}
var firstCipherBytes = cipher.Encrypt(firstPlainBytes, key);
var secondCipherBytes = cipher.Encrypt(secondPlainBytes, key);
firstCipherBytes[0] = firstCipherBytes[1] = firstCipherBytes[2] = 0;
secondCipherBytes[0] = secondCipherBytes[1] = secondCipherBytes[2] = 0;
firstCipherBytes[3] &= 0b00001111;
secondCipherBytes[3] &= 0b00001111;
Array.Reverse(firstCipherBytes);
Array.Reverse(secondCipherBytes);
var firstCipher = BitConverter.ToInt32(firstCipherBytes, 0);
var secondCipher = BitConverter.ToInt32(secondCipherBytes, 0);
if (characteristic.InputDifferential == 4 && characteristic.OutputDifferential == 7)
{
if (i == 11)
{
Console.WriteLine($"LOL {firstCipher} {secondCipher}");
}
}
if ((firstCipher ^ secondCipher) == characteristic.OutputDifferential)
{
var item1 = new PlainCipherPair32(firstPlain, firstCipher);
var item2 = new PlainCipherPair32(secondPlain, secondCipher);
result.Add(Tuple.Create(item1, item2));
}
}
return(result);
}
private List <Tuple <int, int> > GetPossibleSuitableInputs(
DifferentialCharacteristic differentialCharacteristic)
{
var result = new List <Tuple <int, int> >();
for (var i = 0; i < 16; ++i)
{
var secondValue = i ^ differentialCharacteristic.InputDifferential;
if ((sBox[i] ^ sBox[secondValue]) == differentialCharacteristic.OutputDifferential)
{
result.Add(Tuple.Create(i, secondValue));
}
}
return(result);
}