public string DecryptText(string cipherText)
{
int revA = SimpleMaths.ReverseElement(a, M);
StringBuilder decryptedText = new StringBuilder();
foreach (char c in cipherText)
{
if (c == ' ')
{
decryptedText.Append(' ');
continue;
}
int
code = c - 'A',
x = (revA * (code - b)) % M;
if (x < 0)
{
x += M;
}
char next = (x == 26) ? ' ' : (char)(x + 'A');
decryptedText.Append(next);
}
return(decryptedText.ToString());
}
