Collatz-crypto-method

Collatz encoding method with wide format characters.

• Param-- std-c99.
• NDEBUG is undefined in relase mode for assertions.
• Author AMARDJIA Amine
• Date 02/04/2017

Description:

Originally based on Caesar's encryption, but instead of having a key 'D' with fixed offset. Encryption by this method use a variable C key offset witch is depending of the previous C value.

The values ​​of C are determined by collatz's sequence. Aka: syracuse conjecture (Cf. see the wiki) The starting value given to the sequence, is the secret encryption and decryption Key.

 * NB: We take the table of the extended ascii.

• Example:

       C = 15 ->  is the start offset value.
       The sequence C = 15 -> 46 -> 23 -> 70 -> 35 ... etc. Are the offset values for each char.
  

Example of output file:

• Clear -> Atbash encryption:

  Gsrh rh z hrnkov gvhg uli Xloozga hvjfvmxv xibkgl nvgslwv xlnyrmvw drgs zgyzhs nvgslwv 
  FKKVI GVHGV WLMV zmw mld mfnyvih 9876543210 zmw hlnv hkvxrzo xszih : ?!;,<>²&éè'()-_- ç ~ ^ @[]{}+-*/.= % µ *@^
  zmw mld ivk : 8888888888888888888888888888888888888888888888888888 9999999999999999999999999999999999999999999
  

• Atbash -> Collatz encryption with (207) non-printable characters:

  ëÅ�=�ëÕiW•©�;°@Ç���‰ªéÔ{v7�-°4§Îˆ…y©óó!le=S�öëèÀYå±1v ÓžÛAËGíè±,¡èUãñÆ’]3p„{k\ÉmsN�9¼'�Û½¢2éäóį5�©��=��ÅMäÎ��Y��6Ÿ�^�D矸·–U‚�ìa®‰�q2´·1µ+«ŸÇz“¯	=¦ÅKÚ¡ÎyC“��„F-�å›ÏÈuºÓ�Ê:œOv¹=;¯ó½Ôº”Èü„�ÂÙ"Í01ÈYÅ�«ÑÃ:Ì!`5½�@ùæƒe�]—GE?='���¹�IKqû£kÑå3	‰�ÅÁµ¡uß�±…!ÑõsÉÍé?-�“KqÓûe¯�õœdš>HV€
  

• Collatz encryption -> Clear (original message):

  This is a simple test for Collatz sequence crypto methode combined with atbash methode 
  UPPER TESTE DONE and now numbers 0123456789 and some special chars : ?!;,<>²&éè'()-_- ç ~ ^ @[]{}+-*/.= % µ *@^
  and now rep : 1111111111111111111111111111111111111111111111111111 0000000000000000000000000000000000000000000