Re: ssh primer (was Re: pull vs push (was Re: [bk patch] Make cardbus compile in -pre4))

[Harald Arnesen <gurre@start.no>]

Rob Landley <landley@trommello.org> writes:

> Not that it's worth it. Keys get exponentially more difficult to
> brute force as the key length increases. I read part of a book a
> long time ago (might have been called "applied cryptography") that
> figured out that if you could build a perfectly efficient computer
> that could do 1 bit's worth of calculation with the the amount of
> energy in the minimal electron state transition in a hydrogen atom,
> and you built a dyson sphere around the sun to capture its entire
> energy output for the however many billion years its expected to
> last, you wouldn't even brute-force exhaust a relatively small
> keyspace (128 bits? 256 bits? Something like that).
>
> Somebody else here is likely to recognize the above anecdote and give a more 
> accurate reference.  Book title and page number would be good...

Bruce Schneier's "Applied Cryptography" (second edition, may be in the
first edition as well), pages 157-158 ("Thermodynamic Limitations").
-- 
Hilsen Harald.