Software Enigma v0.1.1
 (c) Copyright 2000 by Konrad Rieck <kr@roqe.org>
 Roqefellaz - http://www.roqe.org/senigma

 DOCUMENTATION
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 * What is the Software Enigma?
   
   The Software Enigma is a little application that imitates the original
   behaviour of the Enigma, a cryptographic device that was used in World 
   War II by the german Nazis. The cipher mechanism was cracked by 
   several different parties (polish, english, ...) in the 40s.

   The enigma uses a symmetrical encryption algorithm based on 3 wheels 
   that carry letters in a random order and a reflector wheel also 
   carring letters in random order. A letter passes the 3 wheels, the 
   reflector wheel and then passes the wheels reverse. after each letter 
   the position of the wheels is changed according to the Enigma
   specifications, see the links below.

   You can find several links regarding the history of the Enigma and
   solving its cipher mechanism at:

           http://www.pbs.org/wgbh/nova/decoding
           http://home.us.net/~encore/Enigma/enigma.html
           http://www.trincoll.edu/depts/cpsc/cryptography/enigma.html

   The Software Enigma was designed in order to demonstrate the techniques
   used to crack this mechanism in a coding competition in summer 2000. 
   The Software Enigma is able to work with more than 3 wheels and can
   handle more than 26 different charakters. See the Configuration section
   for more information. 

 * Configuration
  
   Beside the operating system specific configuration that should be made
   in the Makefile, there are some definitions that control the behaviour of
   the cipher algorithm. You can find these definitions in the wheel.h 
   file. Take a look at this file and modify the definitions to fit your 
   needs, e.g. reconstructing the original Enigma behaviour or reconstructing
   the behaviour of later Enigma machines that used 4 wheels. 

 * Compilation

   The cryptographic power of the Enigma and the Software Enigma is based 
   on the wheels that pass the charakters while enciphering, at the first
   step you should generate the senigma.h file that helds exactly the 
   layout of these wheels by executing:

       $ make new-wheels

   Whenever you generate new wheels old messages cannot be encrypted
   therefore you should use the following directive if you want to recompile
   the sengima binary and keep the wheel configuration untouched: 

       $ make senigma

 * Usage   

   The senigma binary en/decrypts an input file and generates an output file
   with the new content. Depending on how many wheels you used for your 
   configuration the command line will look like this: 

       $ ./senigma <key0> <key1> <key2> ... <keyN> <input file> <output file>

   This combination of the keys is the key for en/deciphering the input
   file. 

 * Credits
  
   The code was developed by Konrad Rieck. 
   Thanks for comments and help to Fabian Kroenner and Konrad Kretschmer.