public string Decrypt(string cipherText)
{
StringBuilder clear = new StringBuilder();
for (int i = 0; i < cipherText.Length; i += 2)
{
int c1 = KeySquare1.IndexOf(cipherText[i]) % 5;
int r1 = KeySquare1.IndexOf(cipherText[i]) / 5;
int c2 = KeySquare2.IndexOf(cipherText[i + 1]) % 5;
int r2 = KeySquare2.IndexOf(cipherText[i + 1]) / 5;
clear.Append(alphabet[5 * r1 + c2]);
clear.Append(alphabet[5 * r2 + c1]);
}
return(clear.ToString());
}
public string Decrypt(string encodedText)
{
StringBuilder plainText = new StringBuilder();
for (int i = 0; i < encodedText.Length; i += 2)
{
var i0 = KeySquare1.GetIndex(encodedText[i]);
var row0 = i0 / SQUARE_SIZE;
var col0 = i0 % SQUARE_SIZE;
var i1 = KeySquare2.GetIndex(encodedText[i + 1]);
var row1 = i1 / SQUARE_SIZE;
var col1 = i1 % SQUARE_SIZE;
plainText.Append(ReferenceAlphabet[row0 * SQUARE_SIZE + col1]);
plainText.Append(ReferenceAlphabet[row1 * SQUARE_SIZE + col0]);
}
return(plainText.ToString());
}