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SolitaireCryptoDemo - 1.1

John Eriksson (wmjoers)



A visual demonstration of the steps involved in generating a keystream using Bruce Schneier's Solitaire encryption algorithm.

Featuring smooth animations and descriptions of all steps.

Type "python" to start the demo.

You can also use several commandline options:

  • -r - Setup a shuffled deck.
  • -u - Setup an unkeyed deck.
  • -k KEY - Setup a keyed deck using the algorithm described at
  • -o - Print found keys to standard out.
  • -h - Display this text.


  • python
    starts the demo with a default deck (keyed with "CRYPTONOMICON").
  • python -r
    starts the demo with a shuffled deck.
  • python -u -o
    starts the demo with an unkeyed deck and prints the keys.
  • python -k MYSECRETKEY
    starts the demo with a keyd deck using the passphrase"MYSECRETKEY".


  • Fixed a serious bug in the key finding part of the algorithm. (Thanks to Thomas Knappe for pointing this out!)
  • Fixed some other bugs that I found when tracking down the first one.
  • Changed the key output to show the actual key value instead of the modulus 26 value. To be more compliant to the algorithm description.


Home Page:


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SolitaireCryptoDemo - 1.2 - Oct 6, 2008
SolitaireCryptoDemo - 1.1 - Oct 5, 2008
SolitaireCryptoDemo - 1.0 - Feb 8, 2007 account Comments

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October 8, 2008 2:22pm - Nolan Baker - nickname: (nbaker) - 5/5
Much easier than using a real deck. Great job.
February 9, 2007 4:16am - John Eriksson - nickname: (wmjoers)
Should be somewhat more optimized now.
February 9, 2007 2:15am - John Eriksson - nickname: (wmjoers)
I would say the whole code is kind of dirty *smile*. For this first release I just wanted the output to be correct. When I get some time I'll optimize and tidy this code a bit.
February 8, 2007 8:18pm - Aaron Maupin - nickname: (maupin)
Looks very good. Nice and clean. I noticed that it uses 100% of the cpu, so you should add a pygame.time.wait(x) statement somewhere in your main loop. You also aren't using dirty rects, which would probably speed up the updates of your large window quite a bit.

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