Security Basics mailing list archives
Re: Disk Encryption: aes-xts-plain vs aes-xts-essiv
From: Phoenix Precedent <phoenixprecedent () gmail com>
Date: Fri, 22 May 2009 20:22:57 +0200
It is my understanding that CBC requires ESSIV to prevent watermarking, but XTS does not use a predictable IV, and thus does not. I'd just like confirmation (and possibly light explanation) from someone who knows for sure 100%. Thanks for the response. I'll keep you informed when I find a definitive answer -Phoenix On Fri, 2009-05-22 at 13:17 -0400, jdm wrote:
I'm no cryptographer either, but I believe ESSIV is a protection against watermarking and known plaintext attacks. If I recall correctly, the default state for dm-crypt is insecure since the default, or at least recommended configuration, is 'plain.' The down side is probably increased overhead, but I don't know of any benchmarks for this offhand. Necessary is a relative term, but in my opinion, watermarking and known plaintext attacks are big attack vectors. If you're implementing full disk encryption, you may as well implement it as securely as possible. If I'm wrong on any of the above, please correct me! HTH, --j On Fri, May 22, 2009 at 9:45 AM, <phoenixprecedent () gmail com> wrote:I've searched around and I can't seem to find a straight answer. Is ESSIV necessary in conjunction with XTS? dm-crypt/Luks recommends using "plain," but without justification/explanation. I'm no cryptographer, but a little insight would be helpful. Thanks, Phoenix ------------------------------------------------------------------------ This list is sponsored by: InfoSec Institute Need to pass the CISSP? InfoSec Institute's CISSP Boot Camp in both Instructor-Led and Online formats is the most concentrated exam prep available. Comprehensive course materials and an expert instructor means you pass the exam. Gain a laser like insight into what is covered on the exam, with zero fluff! http://www.infosecinstitute.com/courses/cissp_bootcamp_training.html ------------------------------------------------------------------------
------------------------------------------------------------------------ This list is sponsored by: InfoSec Institute Need to pass the CISSP? InfoSec Institute's CISSP Boot Camp in both Instructor-Led and Online formats is the most concentrated exam prep available. Comprehensive course materials and an expert instructor means you pass the exam. Gain a laser like insight into what is covered on the exam, with zero fluff! http://www.infosecinstitute.com/courses/cissp_bootcamp_training.html ------------------------------------------------------------------------
Current thread:
- Disk Encryption: aes-xts-plain vs aes-xts-essiv phoenixprecedent (May 22)
- Re: Disk Encryption: aes-xts-plain vs aes-xts-essiv jdm (May 22)
- Re: Disk Encryption: aes-xts-plain vs aes-xts-essiv Phoenix Precedent (May 22)
- Re: Disk Encryption: aes-xts-plain vs aes-xts-essiv Aarón Mizrachi (May 25)
- Re: Disk Encryption: aes-xts-plain vs aes-xts-essiv Aarón Mizrachi (May 22)
- Re: Disk Encryption: aes-xts-plain vs aes-xts-essiv jdm (May 22)