[dm-crypt] Switch to XTS mode for LUKS in cryptsetup in 1.6.0 (Was Re: [ANNOUNCE] cryptsetup 1.6.0-rc1)

Arno Wagner arno at wagner.name
Sat Jan 5 20:47:14 CET 2013

On Sat, Jan 05, 2013 at 07:25:52PM +0100, Milan Broz wrote:
> On 01/05/2013 06:20 PM, Arno Wagner wrote:
> > What does RHEL use and recommend? Do they always use
> > AES256-XTS or is AES128-XTS offered as an option (not when
> > douing this manually via commandline). I think there would
> > be some benefit to have the same defauls in distro-independent
> > cryptsetup.
> - Encrypted disk installation is using AES-XTS with 512bit key.
> (installer overwrites default. But I know there was no
> real discussion about AES18/256 before this was changed.)

Always nice to know what happens begind the curtains ;-)

> Installed (anaconda) doesn't allow default cipher/key size change
> but allows to "reuse" existing LUKS device.
> - compiled-in cryptsetup default is the same as upstream (CBC with ESSIV)
> (RHEL7 will use XTS as default, I would like to see the same
> default as upstream.)
> (This was mainly for compatibility reasons but now even RHEL5 can
> map XTS LUKS discs.)
> - RHEL in FIPS mode (dmcrypt/LUKS module is still not validated though)
> allows CBC (only with ESSIV) and XTS with AES128/192/256
> Well, I can get more info from independent people here internally.
> My current opinion is to use aes-xts-plain64 with 256bit key
> (IOW use AES128) as independent default for LUKS.

I think that is probably the best option at the moment.

Arno Wagner,     Dr. sc. techn., Dipl. Inform.,    Email: arno at wagner.name
GnuPG: ID: CB5D9718  FP: 12D6 C03B 1B30 33BB 13CF  B774 E35C 5FA1 CB5D 9718
One of the painful things about our time is that those who feel certainty
are stupid, and those with any imagination and understanding are filled
with doubt and indecision. -- Bertrand Russell

More information about the dm-crypt mailing list