At 11:08 AM 2/22/96 -0500, SINCLAIR DOUGLAS N <sinclai@ecf.toronto.edu> wrote:

What they have gained is the knowledge that their random number source isn't broken. If your RNG started spewing 0 bits by the thousand would you say "This stream is just as likely as any other stream that I can imagine so there is no problem", or "My RNG is broken". Of course, in nice mathematical abstractions your RNG never breaks, but we live in a nasty world of thermal failiures and cold solder joints.

They _haven't_ gained that knowledge, only the knowledge that it isn't _totally_ broken and spewing zeros. For example, the output of while(1) printf("%8c", des(i++, key)); // Pretend syntax is correct would probably pass the randomness tests just fine, in spite of being entirely predictable and having only 56 bits of key plus log(i) bits of state, and is vulnerable to most cryptanalysis attacks on DES systems as well. But it's not a One Time Pad, it's just counter-mode DES. #-- # Thanks; Bill # Bill Stewart, stewarts@ix.netcom.com / billstewart@attmail.com +1-415-442-2215 # http://www.idiom.com/~wcs Pager +1-408-787-1281