********************************************************




by François LEIBER

http://leiber.free.fr


Description


Very fast and simple program, allowing the use of a real and powerful cryptography algorithm on 89, 92+ and V200, using a 80 bits key.


Version 1.13, 04 / 02 / 2004
Copyright 2001-2004 par François LEIBER

Cryptography Algorithm PC1 ( Pukall Cipher 1 )
Copyright Alexandre PUKALL 1991
Utilisation and modifications are free if the name of the author is included in the documentation.

This program is distributed under the GPL license, for further information please refer to the GPL.txt or http://www.gnu.org/licenses/licenses.html#GPL.

Summary


  1. Requirements
  2. How to use PC1
  3. History
  4. Credits
  5. Info

Requirements

  • A Ti-89, a TI-92+ or a Voyager 200 with any ROM or hardware, no kernel requirement.

  • Program PC1, 1.3 KB.

  • For easier use, also send to your calculator PC1.89g (or PC1.9xg for the 92+), and libraries Flib and Flib2.

  • A few bytes free to run it :)

You can place pc1() and the rest in any folder, and I strongly suggest you archive everything.

How to use PC1

You only have to type:

pc1(variable,key)

variable is a string containing the name of the variable to be encrypted/decrypted, key is another string, 10 bytes long or less, containing the key that will be used by the algorithm.

Ex : pc1("doors","FL81@paris")

The program does nothing if there is an error (one of the argument is wrong, or the variable does not exist, or a memory error occurs). Otherwise, it detects automatically if the variable is already crypted or no:
  • If it is already cryted, it tries to decode it. The advantage is that somebody else can't re-encode a variable who is already crypted, making it useless for the original user. Finally, the program tests to know if the key has a chance to be correct or no: if it has no chance to be correct, the program does nothing, otherwise it restores the variable to its state before encryption: this is made so somebody can't decrypt a variable using a wrong key, making it useless for the original user.
  • In the other case, it encodes the variable, transforming it in a variable with the same name, but with type 'cryp'.

I've added all possible protections, the program should never crash (anyway, I'm not responsible for anything that could happen to your TI).

The program's speed is about 2.5 KB/sec in coding-decoding.

PC1 automatically re-archives the variable after its coding-decoding.


History

v1.13 - 04/02/04 - 1 387 bytes
  • Now under the GPL license!
  • Compilation with TI-GCC 0.95b6.


v1.12 - 27/07/02 - 1 181 bytes

  • Compilation using TI-GCC 0.94 beta 18, and test on the new TI Voyager 200 : no problem detected !


v1.11 - 05/20/01 - 1 181 bytes

  • Interruptions are now disabled to speed up coding-decoding.
  • A few lines of the source improved.
  • The interface is now really finished.


v1.1 - 04/01/01 - 1 169 bytes

  • Fixed a memory leak.
  • Added informations in the Status Line.
  • The program now automatically re-archives the variable after its coding-decoding.
  • The program is compiled using the new release of TI-GCC : it is now smaller.
  • I've also included a nice interface in BASIC using Flib, to make the use of PC1 even easier.


v1.0 - 02/20/01 - 1 237 bytes

  • First release, nothing special to say.


Credits

  • First, credits for the algorithm go to Alexandre Pullak, its author.

  • A huge thank to the TI-GCC team, especially Zeljko Juric for all his libraries and his very complete documentation of the different TIOS functions.

  • Rusty Wagner for Virtual Ti.

  • Jean Elchinger who sent me the algorithm source, and pushed me to port it to TI calculators.

  • TATMF <tatmf.free.fr> for his pictures.

  • Me for Flib, so I could make very easily a nice interface :-)


Info

For any suggestion, commentary or bug (that would be quite surprising;-) ), you can e-mail me at:

Francois.leiber@laposte.net

All the ideas are welcome!

All my program updates are first on my (French) webpage:

http://leiber.free.fr

I encourage warmly all those who would like to start C programming but who hesitate, and that's why PC1 is open-source!
This program is distributed under the GPL license, wich means for example that you have the right to change the source code and distibute a modified version, but only if you respect the differents points of the license.


Retour au sommet de la page