From webster: pseudo - closely or deceptively similar to a specified thing. prime number - an integer that can be evenly divided by no other whole number than itself. So prime numbers would go thusly: 1, 2, 3, 5, 7, 11 ... A pseudo prime number would be one that is deceptively similar to a prime number if it could be divided evenly by say two other integers besides itself such as 15, 21, 33, 35 ... Admittedly, this isn't very interesting, but if you had a very large number, say 3000 digits and beyond, you would *expect* that it could be divided by many different integers, especially if we knew it were not prime. The interesting part of all this is that it is an easy task to generate a prime number, even very large ones. Now if we multiply these two numbers together we get another big number although it is not prime, it is very deceptively close to one (since we just created it by multiplying two numbers together albeit 2 very large primes). Now comes the hard part. Factoring this very large pseudo prime number is very difficult and most attempts are reduced to the use of brute force techniques. Even with modern day computers working together full time it could take as long as the earth itself has been in existence to accomplish the task. Our government doesn't like us having secrets. That's why it has classified encryption schemes as munitions. It tried to stop pgp and if it weren't for it getting out in a very broad way early on it may have been stopped and its author thrown in jail. It was touch-and-go for awhile. As it is, the number of digits allowed in a key will be dictated by our government's ability to crack any message in a reasonable time frame using brute force techniques. So in a sense, Andy's point is well taken, and we can safely say that our government hasn't given us anything for which we haven't paid. Even so I would not advise wearing a T-shirt having the RSA Perl script imprinted on it if you plan on traveling abroad. Rich At 12:36 PM 3/26/98 -0500, you wrote: >-----Original Message----- >From: Richard Nowak >To: PICLIST@MITVMA.MIT.EDU >Date: Thursday, March 26, 1998 11:20 AM >Subject: Re: Encryption - OT >>The problem is to show mathematically how to factor a *very* large >pseudo >>prime number into its two prime factors. This is the part I want to see. > > >what exactly is a pseudo prime number???? :-) > > ========================================= = Abolish the Income Tax! Fire the IRS! = = http://www.nrst.org/ = ========================================= ========================================= = Here's a site that wants your views = = http://www.not4irs.org/ = =========================================