Cryptography-Research Digest #821, Volume #1 Sat, 10 Jul 99 15:13:04 EDT Contents: Problems with Bruce Schneier's "Solitaire" (Paul Crowley) ---------------------------------------------------------------------------- From: Paul Crowley <[EMAIL PROTECTED]> Subject: Problems with Bruce Schneier's "Solitaire" Date: 10 Jul 1999 15:29:40 GMT Reply-To: Paul Crowley <[EMAIL PROTECTED]> I've written a fast "C" implementation of Bruce Schneier's hand cipher for a pack of cards, "Solitaire". In doing so I've discovered two surprising facts: * The CPRNG is not reversible. Reversibility is a desirable property of such CPRNGs since it tends to mean long periods and a certain resistance to bias, and the operational notes on the cipher claim that it is. * The output is very biased: successive values are the same with probability around 1/22.5, not 1/26 as with a random keystream. You can pick up a copy of my implementation and run the tests yourself here: http://www.hedonism.demon.co.uk/paul/solitaire/ I welcome your comments and questions. -- __ \/ o\ [EMAIL PROTECTED] Got a Linux strategy? \ / /\__/ Paul Crowley http://www.hedonism.demon.co.uk/paul/ /~\ Employ me! Unix,Linux,crypto/security,Perl,C/C++,distance work. Edinburgh UK. ------------------------------ ** FOR YOUR REFERENCE ** The service address, to which questions about the list itself and requests to be added to or deleted from it should be directed, is: Internet: [EMAIL PROTECTED] You can send mail to the entire list (and sci.crypt.research) via: Internet: [EMAIL PROTECTED] End of Cryptography-Digest Digest ******************************
