On Sun, Jul 25, 2010 at 02:25:32PM +0200, Milan Broz wrote: > > On 07/25/2010 12:34 PM, Arno Wagner wrote: > > This would be a reason to stay away from XTS, something may have > > been subtly messed up. > > > > As a side note, the XTS spec seems to be behind a IEEE paywall, which > > would be another reason not to use it, public standards need to be > > accessible for free. > > You should then suggest not use hardisks and storage technologies too > because most of standards are not accesible for free:-) > </joke> The drafts are free ;-) > Seriously, XTS-AES is FIPS140-2 approved and I see no problem to use it. Well, I basically do not see the algorithm. Maybe searching for 15 Minutes was not enough, but when something is hidden in Crypto, I always become very suspicuous. > Also read > http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/comments/XTS/follow-up_XTS_comments-Ball.pdf > > Yes, final version is not available but draft specification is still there > (this is IEEE business, not hiding algorithm definition IMHO). Have a link to it? Seriously, I suspect XTS is fine, but not finding the description and detailed security analysis online bothers me more than a bit. > Just please note one thing, which is dm-crypt special here: > > default "plain IV" is 32 bit only, so if anyone uses it on >2TB partition > some sectors shares IV (IV generator restarts, opening it to to watermarking > and similar attacks). That was the thing with dm-crypt, yes. > Please _always_ use plain64 (*aes-xts-plain64*) if you want use it for large > devices. (plain64 produces the same IV for <2TB. > Available since 2.6.33, Truecrypt 7 already does that, thanks:-) Ok. Will put that in the FAQ in a few days. Arno -- Arno Wagner, Dr. sc. techn., 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 dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
