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 List <Characteristic> FindBestCharacteristicsDepthSearch(DifferentialAttackRoundConfiguration roundConfiguration,
List <Differential> differentialsList)
{
int round = roundConfiguration.Round;
//Decrement round for recursive call
round--;
//result list
List <Characteristic> resultList = new List <Characteristic>();
//calculate loop border
int loopBorder = CalculateLoopBorder(roundConfiguration.ActiveSBoxes);
for (int i = 1; i < loopBorder; i++)
//Parallel.For(1, loopBorder, i =>
{
Characteristic inputObj = new CipherThreeCharacteristic();
//expected difference
int expectedDifference = GenerateValue(roundConfiguration.ActiveSBoxes, i);
int outputDifferencePreviousRound = expectedDifference;
inputObj.InputDifferentials[round] = expectedDifference;
//start depth-first search
Characteristic retVal = FindBestCharacteristic(round, differentialsList, outputDifferencePreviousRound, inputObj);
// ReSharper disable once CompareOfFloatsByEqualityOperator
if (retVal.Probability != -1)
{
_semaphoreSlim.Wait();
try
{
#if DEBUG
//Console.WriteLine("Case " + roundConfiguration.GetActiveSBoxes() + " finished iteration i = " + i + " / " + loopBorder);
//Console.WriteLine(retVal.ToString());
#endif
resultList.Add(retVal);
}
finally
{
_semaphoreSlim.Release();
}
}
}//);
var sorted = resultList.OrderByDescending(elem => elem.Probability).ToList();
#if DEBUG
foreach (var curRetVAl in sorted)
{
//Console.WriteLine(curRetVAl.ToString());
}
#endif
return(sorted);
}
public DifferentialAttackRoundConfiguration RefreshPairLists(DifferentialAttackRoundConfiguration roundConfig,
List <Differential> diffListOfSBox, DifferentialKeyRecoveryAttack attack, IEncryption encryption)
{
throw new NotImplementedException();
}
public DifferentialAttackRoundConfiguration GenerateConfigurationAttack(int round, bool[] sBoxesToAttack, AbortingPolicy abortingPolicy, SearchPolicy searchPolicy, List <Differential> diffListOfSBox, DifferentialKeyRecoveryAttack attack, IEncryption encryption)
{
if (round <= 1)
{
throw new ArgumentException("To attack round 1, use AttackFirstRound()");
}
else if (sBoxesToAttack == null)
{
throw new ArgumentException("At least one SBox must be specified to attack");
}
DifferentialAttackRoundConfiguration result = new DifferentialAttackRoundConfiguration
{
ActiveSBoxes = sBoxesToAttack,
Round = round,
AbortingPolicy = abortingPolicy,
SearchPolicy = searchPolicy
};
int inputDifference = -1;
int expectedDifference = -1;
double probabilityAccumulated = 0.0;
List <Characteristic> bestCharacteristics = null;
if (result.Round == 3)
{
result.IsLast = true;
}
else if (result.Round == 2)
{
result.IsBeforeLast = true;
}
List <Characteristic> characteristics = FindBestCharacteristicsDepthSearch(result, diffListOfSBox);
//Delete Characteristics which are not usable
List <Characteristic> toDelete = new List <Characteristic>();
foreach (var curCharacteristic in characteristics)
{
bool[] conditionArray = new bool[CipherThreeConfiguration.SBOXNUM];
for (int i = 0; i < CipherThreeConfiguration.SBOXNUM; i++)
{
conditionArray[i] = true;
if (sBoxesToAttack[i])
{
if (GetSubBlockFromBlock(curCharacteristic.InputDifferentials[round - 1], i) == 0)
{
conditionArray[i] = false;
}
}
}
for (int i = 0; i < CipherThreeConfiguration.SBOXNUM; i++)
{
if (conditionArray[i] == false)
{
toDelete.Add(curCharacteristic);
}
}
}
//delete unusable characteristics
foreach (var characteristicToDelete in toDelete)
{
characteristics.Remove(characteristicToDelete);
}
foreach (var characteristic in characteristics)
//Parallel.ForEach(characteristics, (characteristic) =>
{
List <Characteristic> differentialList = FindSpecifiedDifferentialDepthSearch(characteristic.InputDifferentials[0], characteristic.InputDifferentials[round - 1], round, diffListOfSBox);
if (differentialList.Count == 0)
{
//return;
continue;
}
double testProbability = 0.0;
foreach (var curCharacteristic in differentialList)
{
testProbability += curCharacteristic.Probability;
}
_semaphoreSlim.Wait();
try
{
if (testProbability > probabilityAccumulated)
{
probabilityAccumulated = testProbability;
bestCharacteristics = differentialList;
Console.WriteLine("Current best: InputDiff: " + bestCharacteristics[0].InputDifferentials[0] + " ExpectedDiff: " + bestCharacteristics[0].InputDifferentials[2] + " Probability: " + probabilityAccumulated);
}
}
finally
{
_semaphoreSlim.Release();
}
}//);
inputDifference = bestCharacteristics[0].InputDifferentials[0];
expectedDifference = bestCharacteristics[0].InputDifferentials[round - 1];
result.InputDifference = inputDifference;
result.ExpectedDifference = expectedDifference;
result.Characteristics = bestCharacteristics;
//result.Characteristics = new List<Characteristic>();
//result.Characteristics.Add(bestCharacteristics[0]);
result.Probability = probabilityAccumulated;
int pairCount = 16;
result.UnfilteredPairList = GenerateInputPairList(inputDifference, pairCount);
//result.FilteredPairList = FilterPairs(result, diffListOfSBox, attack, encryption, expectedDifference);
result.FilteredPairList = result.UnfilteredPairList;
#if DEBUG
Console.WriteLine("Generated " + result.UnfilteredPairList.Count + " pairs and there stayed " + result.FilteredPairList.Count + " filtered pairs");
#endif
return(result);
}
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);
}
public List <Pair> FilterPairs(DifferentialAttackRoundConfiguration roundConfig, List <Differential> diffListOfSBox,
DifferentialKeyRecoveryAttack attack, IEncryption encryption, int expectedDifferential)
{
//cast to use the object
CipherThreeDifferentialKeyRecoveryAttack cipherFourAttack = attack as CipherThreeDifferentialKeyRecoveryAttack;
if (cipherFourAttack == null)
{
throw new ArgumentNullException(nameof(attack));
}
//contains the filtered pairs
List <Pair> resultList = new List <Pair>();
List <int>[] arrayOfPossibleDifferentialsForSBoxes = new List <int> [CipherThreeConfiguration.SBOXNUM];
int[] arrayOfExpectedInputDifferentialsForSBoxes = new int[CipherThreeConfiguration.SBOXNUM];
for (int i = 0; i < CipherThreeConfiguration.SBOXNUM; i++)
{
arrayOfPossibleDifferentialsForSBoxes[i] = new List <int>();
arrayOfExpectedInputDifferentialsForSBoxes[i] = expectedDifferential;
if (arrayOfExpectedInputDifferentialsForSBoxes[i] == 0)
{
arrayOfPossibleDifferentialsForSBoxes[i].Add(0);
}
}
//iterate over the differentials
foreach (var curDiff in diffListOfSBox)
{
//Skip 0 InputDiff / OutputDiff
if (curDiff.InputDifferential == 0)
{
continue;
}
for (int i = 0; i < CipherThreeConfiguration.SBOXNUM; i++)
{
if (arrayOfExpectedInputDifferentialsForSBoxes[i] == curDiff.InputDifferential)
{
arrayOfPossibleDifferentialsForSBoxes[i].Add(curDiff.OutputDifferential);
}
}
}
//check all pairs for the conditions
foreach (var curPair in roundConfig.UnfilteredPairList)
{
int cipherTextLeftMember = encryption.EncryptBlock(curPair.LeftMember);
int cipherTextRightMember = encryption.EncryptBlock(curPair.RightMember);
cipherTextLeftMember = PartialDecrypt(attack, cipherTextLeftMember);
cipherTextRightMember = PartialDecrypt(attack, cipherTextRightMember);
int diffOfCipherText = (cipherTextLeftMember ^ cipherTextRightMember);
int[] diffOfCipherTextSBoxes = new int[CipherThreeConfiguration.SBOXNUM];
bool[] conditionsOfSBoxes = new bool[CipherThreeConfiguration.SBOXNUM];
for (int i = 0; i < CipherThreeConfiguration.SBOXNUM; i++)
{
diffOfCipherTextSBoxes[i] = diffOfCipherText;
conditionsOfSBoxes[i] = false;
}
for (int i = 0; i < CipherThreeConfiguration.SBOXNUM; i++)
{
foreach (var possibleOutputDiff in arrayOfPossibleDifferentialsForSBoxes[i])
{
if (possibleOutputDiff == diffOfCipherTextSBoxes[i])
{
conditionsOfSBoxes[i] = true;
}
}
}
bool satisfied = true;
for (int i = 0; i < CipherThreeConfiguration.SBOXNUM; i++)
{
if (conditionsOfSBoxes[i] == false)
{
satisfied = false;
}
}
if (satisfied)
{
resultList.Add(curPair);
}
}
return(resultList);
}
public List <Characteristic> FindBestCharacteristicsHeuristic(DifferentialAttackRoundConfiguration roundConfiguration, List <Differential> differentialsList)
{
throw new NotImplementedException();
}
public List <Characteristic>[] FindAllDifferentialsDepthSearch(DifferentialAttackRoundConfiguration roundConfiguration, List <Differential> differentialsList)
{
throw new NotImplementedException();
}