[geeks] Interesting: hardware security token for PayPal

[Geoffrey S. Mendelson]

On Wed, Apr 04, 2007 at 11:08:45AM -0400, Charles Shannon Hendrix wrote:
> Geoffrey mentioned (I think, I'm lost in the thread now) having a card
> which never repeated.

I don't think I said that, but I probably impled it. Since the real 
"magic number" is something like 14 digits long, it has to evenutaly
repeat a single number, which would probably be a long time after
all of us, the computers that check the code and the unit itself
long since stopped functioning. 

As far the number you enter repeating the same number it has to. Six digits
is one in a million, and how long is a million minutes? But repeating
two numbers in sequence is darn near impossible, three even less and
so on.

When he was in 7th grade, my son Paul did a sicence fair project, all by
himself, where he wrote a basic program to track the random number
generator in Microsoft basic. In order to finish it in reasonable time,
using a 12mHz 80286 PC he tracked three digits of significance. 

He produced a nice set of posters showing his results, how quickly it repeated
itself and so on. Since his project was not mentored (done by an adult),
it was not flashy and eye catching. Although similar work had recently 
been awarded a PhD. at MIT, in his elementry school, it did not even
receive an honerable mention.  

Geoff.
-- 
Geoffrey S. Mendelson, Jerusalem, Israel gsm at mendelson.com  N3OWJ/4X1GM
IL Voice: (07)-7424-1667  Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
Visit my 'blog at http://geoffstechno.livejournal.com/