enigma.txt

ENIGMA3模拟WW II加密算法(含EXE文件)

                            ENIGMA

        A simulator for the WW II cryptographic engine


            (c) 1995 by Andreas G. Lessig, Hamburg
                          





(1) Introduction

The program ENIGMA was written to simulate the three rotor version
of the german Enigma. I wanted it to come as close to the original
as possible. A second requirement was to keep it as portable as
possible. This led to some limitations I couldn't avoid:

 1. The original Enigma produces a horrible sound when a key is
    pressed. I wasn't able to program that. So my program remains
    silent.

 2. On a PC the driver ansi.sys is required. I know it isn't very
    popular, but there is no way of programming graphics portable
    in C.

 3. The PC is the only System on which the programs makes use of
    colours. On other system the ENIGMA is white on black or black
    on white, depending on the graphic abilities of the system and
    my knowledge in programming graphic routines for it.

    You might want to write your own graphic routines. I won't
    prohibit that, but follow the restrictions in the file 
    "porting.txt". There you also find some documentation for the
    graphic routines.

 4. Due to a lack of time I didn't program aroutine to simulate the
    failure of single lamps which occured frequently at a real 
    Enigma I was comparing my program with.

I hope you nevertheless enjoy it.

                   Andreas Lessig, 27.4.1995





(2) Legal Notice  

(a) The program comes "as is". There is no implied warranty whatsoever.
    I don't guarantee for the functuality nor do I pay if you manage to
    trash your system with it.

(b) You may use it for non comercial purposes. If you find a way to make 
    money out of it, you need a license to do so. 
    Just contact me and I'm sure we will come to an agreement. My current
    email adress is
           [e-mail]

(c) You might copy the program for private purposes and distribute it on
    a noncomercial base.
    Again as long as you just charge your own costs for that, I encourage 
    you to spread my program. If you make profit out of it, I want my 
    share.
    There is one restriction. This file, "porting.txt" and the source code 
    form a package. You might only distribute them together.

(d) If you want to change the graphic routines or port the program to 
    another system, feel free to do so.
    But mark all changes as yours, update the log at the beginning of the 
    source and make an entry at the title screens, so everybody knows, this
    version has be altered.
    Make all changes which aren't portable 100% depending on a switch. How to
    do this is described in "porting.txt".  



(3) Getting started

The program has three options:

    -c simulates a green (only PC) celluloid cover, through wich only the
       lit windows can be seen. 

    -d DEBUG option. Shows before the initial screen the assumpions the
       program makes about your system. During encryption all steps of the
       process are shown.

    -t simulates a tty connected to the enigma. On a  white strip you can 
       see the last 65 encrypted characters formatted in groups of five.
       Such a device wasn't used with the original Enigma. There were some
       tests, but according to my sources technical problems led to the
       suspension of this projekt.

After you have called the program you might see the debug screen or the 
first title screen. Read every page carefully and press then <return>.

After three or for presses you should enter the setup. Here are the current 
settings shown and you have the possibility to change them.

(a) Plugboard

    Just press <p> and you enter the plugboard menu. Here you may enter
    new wirings to the plugboard. If you enter a plug already used by 
    another connection that connection is removed.
    
    With <ESC> you get back to the setup.

(b) Rotors
    
    With <c> you get to the rotor setup. Here you you may choose rotors and
    reflektor. You also can enter the ringsetting for each rotor.

    <ESC> brings you back to the main setup.

(c) Operating the Enigma

    With <e> you get to the simulation. Here you see in the lower part a 
    representation of the keyboard. If you press a key, its representation 
    will change its colour.
    Above you see a representation of the windows. Everytime a Character is 
    entered one window will be lit by a bulb behind it. This way the result
    of the encryption is displayed to the operator.
	Over the windows you see the rotors. At least one of them will turn 
    before each encryption. You might use the arrow keys to change their 
    initial position. You might also use <Cntrl-b> and <Cntrl-f> to turn one
    rotor and <Cntrl-p> and <Cntrl-n> to choose which rotor it shall be.

    <F1> or <1> brings you back to the setup

    <ESC> exits the program  
    

(4) Acknowledgements

This program wouldn't have existed without Professor Klaus Brunnstein,
who borrowed a real Enigma from the Bundesamt f"ur Sicherheit in der
Informationstechnik, and Vesselin Bontchev, who explained it and found
the technical data which was indispensible for the realization of this 
project.