CDR: Re: why should it be trusted?

[Ray Dillinger]

On Tue, 17 Oct 2000, Kerry L. Bonin wrote:

>Extrapolate capabilities from the EFF DES crack project and you are
>somewhat closer (1536 ASIC w/ 24 cores/ASIC yielded 4.52 days/crack of 56
>bit keyspace), then take into consideration the advantages of using more
>sophisticated semiconductor processes (ECL 15 years ago, GaAs on Sapphire
>today) and the higher clock rates that go with that (40MHz to well > 1GHz),
>and rerun your numbers.  Instead of a small cabinet, fill floors of
>buildings with these machines, and you have realtime cracking farms.

You have realtime cracking farms for *some* ciphers.  I have always 
figured it this way: 

They get two orders of magnitude for being "ahead of the curve"
   in knowledge and technique.
They get five orders of magnitude of speed for custom hardware. 
They get seven orders of magnitude for massively parallel hardware. 

That totals 14 orders of magnitude (and I think that's generous). 

So use keys that are six bytes longer than a "reasonable" opponent 
could crack.  problem solved. 2048-bit RSA is still way out of 
their league.  


>As for my own comments, I wrote layout and design tools used on these NSA
>custom chips in the mid 80's, certified for use with the "NSA Standard Cell
>Library" by their chip designers (they were just one of the customers of
>the CAD/CAM/CAE software I worked on back then...)

Interesting.  I thought that was the sort of thing that you could 
tell the people who'd done it because they were the ones who weren't 
allowed to talk about it.

				Bear