Design document

#

$Id$

Key handling

Key => encrypt, decrypt
    SKey
    TKey
    SCKey
    ChaoKey

Cipher handling

module Cipher

SimpleCipher => encode, decode
>   Substitution
    >   ChaoCipher
    >   Caesar
    >   Rot13
    >   Wheatstone cryptograph
>   Transposition
>   Nihilist
>   ADFGX
>   ADFGVX
>   VIC
>   SECOM