Security Basics mailing list archives
Re: FDE and integrity of OS Was: How to Test HDD Encryption
From: Ansgar -59cobalt- Wiechers <bugtraq () planetcobalt net>
Date: Wed, 14 Nov 2007 17:25:10 +0100
On 2007-11-14 Alexander Klimov wrote:
On Tue, 13 Nov 2007, Ansgar -59cobalt- Wiechers wrote:But isn't FDE primarily targeted at protecting data from lost or stolen systems? A bit over 40% of data breaches are due to lost or stolen devices.That's its primary use. However, FDE also protects the integrity of the operating system while the computer is not running.FDE can make tampering with your OS slightly harder but it does not protect OS integrity in any strong sense. Consider the following example (inspired by `Vbootkit' and `Blue Pill'): attacker who has temporary physical access to your computer (while it is switched off) changes the system so that attacker's software loads first (the attacker changes boot-sector or reflash BIOS), this software loads the rest of the system in a virtual environment.
These are additional attack vectors, none of which is addressed by file-level encryption. I didn't say that FDE is a silver bullet, but it does address attack vectors that file-level encryption doesn't, while the issues file-level encryption takes care of (aside from protecting data while the computer is switched off) are already addressed by the operating system itself. That said, manipulations of boot sector and MBR can be mitigated by booting off other media (CD-R for instance), while BIOS manipulations can only be mitigated by ensuring physical security AFAICS. Regards Ansgar Wiechers -- "All vulnerabilities deserve a public fear period prior to patches becoming available." --Jason Coombs on Bugtraq
Current thread:
- RE: How to Test HDD Encryption, (continued)
- RE: How to Test HDD Encryption Eric White (Nov 13)
- Re: How to Test HDD Encryption Ansgar -59cobalt- Wiechers (Nov 13)
- RE: How to Test HDD Encryption jfvanmeter (Nov 13)
- Re: How to Test HDD Encryption Ansgar -59cobalt- Wiechers (Nov 13)
- RE: How to Test HDD Encryption Eric White (Nov 13)
- Re: RE: How to Test HDD Encryption jim . lehman (Nov 13)
- Re: RE: How to Test HDD Encryption Ansgar -59cobalt- Wiechers (Nov 13)
- FDE and integrity of OS Was: How to Test HDD Encryption Alexander Klimov (Nov 14)
- Re: FDE and integrity of OS Was: How to Test HDD Encryption Mike Hale (Nov 14)
- RE: FDE and integrity of OS Was: How to Test HDD Encryption Craig Wright (Nov 14)
- Re: FDE and integrity of OS Was: How to Test HDD Encryption Ansgar -59cobalt- Wiechers (Nov 14)
- Re: RE: How to Test HDD Encryption Ansgar -59cobalt- Wiechers (Nov 13)
- RE: How to Test HDD Encryption Eric White (Nov 14)
- Re: How to Test HDD Encryption Ansgar -59cobalt- Wiechers (Nov 14)
- Re: How to Test HDD Encryption Ansgar -59cobalt- Wiechers (Nov 14)