/// <summary>
/// Decipher a ciphertext into plaintext.
/// </summary>
/// <param name="ciphertext">The ciphertext to decipher.</param>
/// <returns>The plaintext.</returns>
public string Decipher(string ciphertext)
{
char[][] digraphs;
StringBuilder plaintext = new StringBuilder();
digraphs = CipherMethods.SplitDigraphs(ciphertext);
for (int i = 0; i <= digraphs.Length; i++)
{
plaintext.Append(Decipher(digraphs[i][0], digraphs[i][1]));
}
return(plaintext.ToString());
}
/// <summary>
/// Encipher a plaintext string into ciphertext.
/// </summary>
/// <param name="plaintext">The plaintext to encipher.</param>
/// <returns>The ciphertext.</returns>
public string Encipher(string plaintext)
{
char[][] digraphs;
StringBuilder ciphertext = new StringBuilder();
digraphs = CipherMethods.GenerateDigraphs(plaintext);
for (int i = 0; i <= digraphs.Length; i++)
{
ciphertext.Append(Encipher(digraphs[i][0], digraphs[i][1]));
}
return(ciphertext.ToString());
}