Two tidbits of potential interest

[David Shaw]

First of all, someone has factored a 512-bit RSA key (the one used to  
protect a TI programmable calculator, it seems).  It took 73 days on a  
dual-core 1900Mhz Athlon64.  It took just under 5 gigs of storage and  
around 2.5 gigs of RAM.  In other words: not much at all.  It's not  
some big distributed project - rather it's a single guy who wanted to  
factor it and just left it running in the background for 2 and a half  
months.  (This is actually a month old - forgot to send it before now).

http://www.unitedti.org/index.php?showtopic=8888

Also, here's the Stick Figure Guide to AES:

http://www.moserware.com/2009/09/stick-figure-guide-to-advanced.html

David