Full Disclosure mailing list archives
Re: Possible issues with encrypted Linux filesystems?
From: Steve Pinkham <steve.pinkham () gmail com>
Date: Mon, 13 Dec 2010 11:53:28 -0500
Disclaimer: I'm not a cryptographer. I don't even play one on TV.
I'm now worried that if an attacker knows, or "guesses" that you are using, say, CentOS Linux 5.5, (or at least some mutation of Red Hat), he might use this knowledge of "known artefacts" to his advantage, by starting out from the data he knows "must be there", and looking for it's "patterns". I don't know... This may be a longshot, wishful thinking or both, but somehow it feels to me like it's a lot easier to break a code when you already know exactly what the decrypted data is, and what it looks like.
These sorts of attacks were the design criteria for modern disk encryption modes. http://en.wikipedia.org/wiki/Disk_encryption_theory XTS is the current best mode for FDE. CBC-ESSIV seems "strong enough" against most reasonable attacks, which is why it is still the default in some software. If an attacker has access to your computer twice, they're going to install a keylogger, not image your data and hope you change the sectors with sensitive data and rewrite them in the same place. The strength and protection of your key material should be your primary concern. (Actually, I'd say your primary concern should be keeping a clean conscience, but that's out of the scope of this discussion. ;-) You are much more likely to be compromised by malware, a keylogger, a hidden camera pointed at your keyboard, or "thermorectal cryptanalysis" then any of the things you are worried about. Physical security trumps other concerns. Obligatory XKCD: http://xkcd.com/538/ -- | Steven Pinkham, Security Consultant | | http://www.mavensecurity.com | | GPG public key ID CD31CAFB |
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Current thread:
- Possible issues with encrypted Linux filesystems? Levente Peres (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? news (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? Jeffrey Walton (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? Everhart, Glenn (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? Jeffrey Walton (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? Everhart, Glenn (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? Everhart, Glenn (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? Steve Pinkham (Dec 13)
- Re: Possible issues with encrypted Linux filesystems? Jeffrey Walton (Dec 14)