On Sat, Feb 19, 2011 at 03:39:07AM +1100, Eric Bauman wrote: > Hi, > > When using LVM with LUKS, is it more secure to: > 1 - have a single container containing LVM, or > 2 - LVM containing multiple containers? Technologically, security is the same. Reliability is lower on (2) as you have more headers you can damage and lose. As with RAID, encryption should sit on top, not somewhere in between. With regard to interface and usability (allways _very_ important in security!), (1) is a lot better, since (2) requires you to unlock multiple containers and keep multiple passowrds or enter the same password multiple times. That makes option (1) the thing to do and option (2) a curiosity that violates a number of principles, among them simplicity, crypto as last/highest layer below the filesystem, leas amount of credentials, least exposure of the credentials. > I typically randomise my block device before creating a LUKS container > on it. Option 2 would seem to reduce the effectiveness of this because > LVM will give clues to where real data might be. I don't follow. That encrypted data is present is obvious from the LUKS header. What is in the container(s) is as opaque in (1) as it is in (2), given that cryptographically strong randomness is used for the overwrite (I use plain dm-crypt with a random password and overwrite with conventional, mt19997-generated randomness). 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
