public string Decrypt(string ciphertext, char[,] key)
{
int[] rowIndexes = new int[ciphertext.Length],
columnIndexes = new int[ciphertext.Length];
for (int i = 0; i < ciphertext.Length; i++)
{
Tuple <int, int> offsets = PolybiusSquare.FindOffsets(key, ciphertext[i]);
columnIndexes[i] = offsets.Item1;
rowIndexes[i] = offsets.Item2;
}
StringBuilder result = new StringBuilder(ciphertext.Length);
int[] concatenated = new int[ciphertext.Length * 2];
for (int i = 0; i < ciphertext.Length; i++)
{
concatenated[2 * i] = rowIndexes[i];
concatenated[2 * i + 1] = columnIndexes[i];
}
for (int i = 0; i < ciphertext.Length; i++)
{
result.Append(key[concatenated[i + ciphertext.Length], concatenated[i]]);
}
return(result.ToString());
}
public string Decrypt(string ciphertext, char[, ][,] key)
{
char[] result = new char[ciphertext.Length];
for (int i = 0; i < ciphertext.Length - 1; i++)
{
if (Char.IsLetter(ciphertext[i]) && Char.IsLetter(ciphertext[i + 1]))
{
Tuple <int, int> firstPosition = PolybiusSquare.FindOffsets(key[1, 0], Char.ToUpper(ciphertext[i])),
secondPosition = PolybiusSquare.FindOffsets(key[0, 1], Char.ToUpper(ciphertext[i + 1]));
if (firstPosition == null || secondPosition == null)
{
result[i] = ciphertext[i];
result[i + 1] = ciphertext[i + 1];
i++;
continue;
}
result[i] = key[0, 0][secondPosition.Item1, firstPosition.Item2].ToSameCaseAs(ciphertext[i]);
result[i + 1] = key[1, 1][firstPosition.Item1, secondPosition.Item2].ToSameCaseAs(ciphertext[i + 1]);
i++;
}
else
{
result[i] = ciphertext[i];
}
}
return(new String(result));
}
public string Encrypt(string plaintext, char[,] key)
{
// F L E E A T O N C E
// 4 4 3 3 3 5 3 2 4 3
// 1 3 5 5 3 1 2 3 2 5
int[] rowIndexes = new int[plaintext.Length],
columnIndexes = new int[plaintext.Length];
for (int i = 0; i < plaintext.Length; i++)
{
Tuple <int, int> offsets = PolybiusSquare.FindOffsets(key, plaintext[i]);
columnIndexes[i] = offsets.Item1;
rowIndexes[i] = offsets.Item2;
}
StringBuilder result = new StringBuilder(plaintext.Length);
// 4 4 3 3 3 5 3 2 4 3 1 3 5 5 3 1 2 3 2 5
int[] concatenated = rowIndexes.Concat(columnIndexes).ToArray();
// 44 33 35 32 43 13 55 31 23 25
// U A E O L W R I N S
for (int i = 0; i < concatenated.Length; i += 2)
{
result.Append(key[concatenated[i + 1], concatenated[i]]);
}
return(result.ToString());
}
protected override string Crypt(string text, char[][,] key)
{
char[] result = new char[text.Length];
for (int i = 0; i < text.Length - 1; i++)
{
if (Char.IsLetter(text[i]) && Char.IsLetter(text[i + 1]))
{
Tuple <int, int> firstPosition = PolybiusSquare.FindOffsets(key[0], Char.ToUpper(text[i])),
secondPosition = PolybiusSquare.FindOffsets(key[1], Char.ToUpper(text[i + 1]));
if (firstPosition == null || secondPosition == null)
{
result[i] = text[i];
result[i + 1] = text[i + 1];
i++;
continue;
}
result[i] = key[0][secondPosition.Item1, firstPosition.Item2].ToSameCaseAs(text[i]);
result[i + 1] = key[1][firstPosition.Item1, secondPosition.Item2].ToSameCaseAs(text[i + 1]);
i++;
}
else
{
result[i] = text[i];
}
}
return(new String(result));
}