On Fri, Feb 22, 2008 at 11:45:14AM -0800, Bill Broadley wrote: > > Do today's CPUs allow for pinning a small amount of data in cache? Say 16 > bytes or whatever is needed for an encryption key? No. There is no structure for that. Caches do not work this way. You could put crypto-keys into CPU registerts. But for numerous reasons this is a very bad idea. And it would not help either. > Seems like it would be > significantly harder to remove a CPU (especially from a laptop) and that > CPUs likely initialize the cache when power is provided. y > > That way the key is never in memory, cache size is reduced by a trivial > amount, and the key would be significantly harder to recover. They key would still be in memory, as it can be derived from the cipher-setup. Also your "significantly harder" is pure conjecture. Would you people please stop the half-backed suggestions and get a grip? This is not a major issue and it is not a surprise either! Also when Ed Felton writes that "he could easily", then this does still not mean that your average industrial spy has a chance. If your attacker is above average, disk-encryption as the only protection of a running (!) system is obviously not enough. No competent security expert should be surprised by that. This is not a new problem, the paper just puts some concrete numbers of an attack that everybody with the right knowledge expected to be feasible anyways. Arno -- Arno Wagner, Dipl. Inform., CISSP --- Email: arno@xxxxxxxxxxx GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier --------------------------------------------------------------------- dm-crypt mailing list - http://www.saout.de/misc/dm-crypt/ To unsubscribe, e-mail: dm-crypt-unsubscribe@xxxxxxxx For additional commands, e-mail: dm-crypt-help@xxxxxxxx
