static void AttackLastRound()
{
Encryption encryption = new Encryption();
Analysis analysis = new Analysis();
Console.WriteLine("Current keys: " + encryption.PrintKeys());
//analysis the sbox
List <Differential> diffList = analysis.CountDifferentialsSingleSBox();
bool[] attackSBox = new bool[] { true };
//Check the attack new
CipherThreeDifferentialKeyRecoveryAttack keyRecoveryConfiguration = new CipherThreeDifferentialKeyRecoveryAttack();
SearchPolicy curSearchPolicy = SearchPolicy.FirstBestCharacteristicDepthSearch;
AbortingPolicy curAbortingPolicy = AbortingPolicy.Threshold;
//attack round 3
DifferentialAttackRoundConfiguration configRound3SBox1 = analysis.GenerateConfigurationAttack(3, attackSBox, curAbortingPolicy, curSearchPolicy, diffList, keyRecoveryConfiguration, encryption);
DifferentialAttackRoundResult resultRound3SBox1 = analysis.RecoverKeyInformation(keyRecoveryConfiguration, configRound3SBox1, encryption);
keyRecoveryConfiguration.RoundConfigurations.Add(configRound3SBox1);
keyRecoveryConfiguration.RoundResults.Add(resultRound3SBox1);
//Result
keyRecoveryConfiguration.Subkey3 = resultRound3SBox1.PossibleKey;
keyRecoveryConfiguration.RecoveredSubkey3 = true;
Console.WriteLine(keyRecoveryConfiguration.printRecoveredSubkeyBits());
}
public DifferentialAttackRoundResult RecoverKeyInformation(DifferentialKeyRecoveryAttack attack,
DifferentialAttackRoundConfiguration configuration, IEncryption encryption)
{
if (configuration.ActiveSBoxes == null)
{
throw new ArgumentException("activeSBoxes should contain at least one active SBox");
}
DifferentialAttackRoundResult roundResult = new DifferentialAttackRoundResult();
//Generate border for the loop
int loopBorder = CalculateLoopBorder(configuration.ActiveSBoxes);
for (int i = 0; i < loopBorder; i++)
//Parallel.For(0, loopBorder, i =>
{
int guessedKey = GenerateValue(configuration.ActiveSBoxes, i);
KeyProbability curTry = new KeyProbability()
{
Counter = 0, Key = guessedKey
};
foreach (var curPair in configuration.FilteredPairList)
{
Pair encryptedPair = new Pair()
{
LeftMember = encryption.EncryptBlock(curPair.LeftMember), RightMember = encryption.EncryptBlock(curPair.RightMember)
};
//reverse round with the guessed key
int leftMemberSingleDecrypted = ReverseSBoxBlock(encryptedPair.LeftMember ^ curTry.Key);
int rightMemberSingleDecrypted = ReverseSBoxBlock(encryptedPair.RightMember ^ curTry.Key);
int differentialToCompare = (leftMemberSingleDecrypted ^ rightMemberSingleDecrypted);
if (differentialToCompare == configuration.ExpectedDifference)
{
curTry.Counter++;
}
}
//synchronize access to resultList
_semaphoreSlim.Wait();
try
{
roundResult.KeyCandidateProbabilities.Add(curTry);
}
finally
{
_semaphoreSlim.Release();
}
}//);
//sort by counter
KeyProbability bestPossibleKey = new KeyProbability()
{
Counter = 0, Key = 0
};
foreach (var curKey in roundResult.KeyCandidateProbabilities)
{
if (curKey.Counter > bestPossibleKey.Counter)
{
bestPossibleKey = curKey;
}
}
roundResult.PossibleKey = bestPossibleKey.Key;
roundResult.Probability = bestPossibleKey.Counter / (double)configuration.UnfilteredPairList.Count;
roundResult.ExpectedProbability = configuration.Probability;
roundResult.KeyCandidateProbabilities = roundResult.KeyCandidateProbabilities.OrderByDescending(item => item.Counter).ToList();
#if DEBUG
Console.WriteLine("Expected probability: {0:N4}" + " Expected count: " + (configuration.Probability * configuration.UnfilteredPairList.Count), configuration.Probability);
foreach (var curKeyProbability in roundResult.KeyCandidateProbabilities)//.GetRange(0,3))
{
Console.WriteLine("Guessed key: " + curKeyProbability.Key + " Count: " + curKeyProbability.Counter + " Probability: {0:N4}", ((curKeyProbability.Counter / (double)configuration.UnfilteredPairList.Count)));
}
#endif
return(roundResult);
}
