On Thu, 16 Jul 2009, Robert Wann wrote:
> There exists an effective solution to mitigate the OS attacks (warm boot > as being described by Garrett) using all disk drives including SED and > FDE. This can be done without a TPM or any other extra components as > suggested by Dmitry & Darren. > > Garrett said: > <Thanks for the info, Lark. > > So the attack vector is reduced to: > 1. the machine is on* (like if the user locks his screen & walks away for a > moment), and then > 2. someone steals the laptop (leaving it on), and then > 3. restarts the machine using a boot disc or bootable USB stick.> I am missing something very elementary here - why shouldn't the screen lock turn off decryption? Why would the system need to wait for the reset? Is it so that threads can continue to execute? Is that a widespread requirement on a laptop? Daniel Feenberg > > A warm boot such as Ctl-Alt-Del causes SATA host to issue COMRESET which > in turn resets device protocol stacks without power being interrupted. > What SED and FDE would need to perform is to reset the crypto engine > upon COMRESET to invalidate the AES secret key of either the disk > controller (if the crypto engine is embedded within the disk controller) > or the separate crypto controller working in conjunction with the disk > controller. The solution is indifferent to the boot sequence. > > The X-Wall MX (http://www.enovatech.net/products/mx_info.htm) does just > that. > > Thanks, > > Robert Wann > CTO > Enova Technology Corp. > www.enovatech.com; [email protected]; > > ----- Original Message ----- > From: Garrett M. Groff > To: [email protected] > Sent: Thursday, July 16, 2009 5:54 AM > Subject: Re: [FDE] Q concerning hardware-based encryption/security > > > I'm definitely not suggesting that hardware-based FDE should also handle OS > attacks, attacks on RAM, etc. That would certainly fall out of scope with the > purpose of the drive. The only remaining concern I have is that hardware FDE > doesn't require re-authentication on reboot. Again, hibernation or shutdown > defeat this attack scenario, but security is about risk assessment, so that > is what I'm trying to gauge here (the relative risks associated with hardware > FDE vs software FDE). > > ------------------ > > Changing gears slightly... > > Can anyone describe the anti-hammering that is built into the Seagate FDE > drive (to preclude brute-forcing the authentication passphrase)? > > G > > > ----- Original Message ----- > From: Dmitry Obukhov > To: [email protected] > Sent: Tuesday, July 14, 2009 3:52 PM > Subject: Re: [FDE] Q concerning hardware-based encryption/security > > > Hi Garrett, > > The described attack is not in the SED threat model. As Lark said, we are > focusing on data-at-rest. Basically, you described hi-jack attack, when > powered-on computer is stolen. You will need one more element in the system, > proximity sensor, to mitigate this attack. There are plenty of sensors on the > market: > > For example: > > http://www.officedepot.com/a/products/823445/Tripp-Lite-Wireless-USB-Proximity-Lock/?cm_mmc=Mercent-_-Google-_-Security_Tools_and_Cleaning-_-823445&mr:trackingCode=0DD648A0-CD65-DE11-B7F3-0019B9C043EB&mr:referralID=NA > > If you have built-in Bluetooth, you can use software solution like this one: > http://www.bluetoothpassport.com/ > or even freeware open source: > http://members.lycos.co.uk/wuul/bluelock/readme.html > > You may need to change sensor software configuration to hibernate instead of > sleep or starting screensaver. In combination with hardware disk encryption > it will give you good protection against hijack and even against followed > cold boot attack on hi-jacked machine. > > Dmitry > > > > > > From: [email protected] [mailto:[email protected]] On > Behalf Of Garrett M. Groff > Sent: Wednesday, July 08, 2009 11:30 AM > To: [email protected] > Subject: Re: [FDE] Q concerning hardware-based encryption/security > > Thanks for the info, Lark. > > So the attack vector is reduced to: > 1. the machine is on* (like if the user locks his screen & walks away for a > moment), and then > 2. someone steals the laptop (leaving it on), and then > 3. restarts the machine using a boot disc or bootable USB stick. > > Begging the question: Are there ways of mitigating that avenue of attack > beyond just changing the boot sequence in the BIOS & password-protecting the > BIOS setup? > > * I understand many other vulnerabilities exist on running operating > systems, such as buffer overflow attacks on system services via the network, > but I find that avenue of attack less likely than simply using a boot disc > (as described above), esp as self-encrypting drives become more widespread. > > > ----- Original Message ----- > From: Lark Allen > To: [email protected] > Sent: Wednesday, July 08, 2009 11:42 AM > Subject: Re: [FDE] Q concerning hardware-based encryption/security > > > Garrett, > > The alternate boot threat you describe cannot be executed against the > Seagate Momentus FDE drives. Whenever power is removed from the drive, > either at full system shutdown, or when the system goes into hibernation, the > drive locks and all user data, including the hibernation file is encrypted > and unavailable. When the system is powered up the FDE drive is locked. If > an alternate system is booted, the drive will only appear to have a 128MB > available, which is the protected read-only partition on the drive which > stores the shadow master boot record which is used to provide the pre-boot > authentication for unlocking the drive by an authorized user. Once the drive > is unlocked, then the normal boot process or return from hibernation will > execute. There is no possibility for alternate boot scenarios which will be > able to find the drive in an unlocked state. > > The Wave Embassy software you mentioned for managing the setup and security > settings for the Seagate FDE drive, forces Windows to use hibernate mode, > even if standby mode is selected by the user. In Dell systems, Seagate, > Wave, and Dell worked together to create a solution for secure standby mode, > so for Dell systems both hibernate and standby modes are supported with full > security. > > Lark Allen > > Wave Systems Corp. > From: [email protected] [mailto:[email protected]] On > Behalf Of Garrett M. Groff > Sent: Monday, July 06, 2009 11:23 AM > To: [email protected] > Subject: [FDE] Q concerning hardware-based encryption/security > > I have a concern about self-encrypting drives, specifically Seagate Momentus > FDE. While the idea looks quite brilliant, my understanding is that the user > is only prompted for credentials when booting from a cold machine (one that > has been shut down completely). If that's correct, then that presents the > following vector of attack: > > Bad Guy catches machine in standby (or hibernate?) mode. Bad Guy wakes > machine & then restarts it, booting to a USB stick (or CD) rather than the > HDD. Since HDD is already authenticated, Bad Guy mounts file system & reads > (or writes!) data directly off of HDD. > > Can someone provide technical information that confirms or denies this > potential attack vector? I'm specifically looking at Seagate's Momentus FDE > drive w/ Wave's Embassy Suite, though other vendors would logically suffer > the same vulnerability. > > Thanks. > > > > _______________________________________________ > FDE mailing list > [email protected] > http://www.xml-dev.com/mailman/listinfo/fde > > > > > > > > _______________________________________________ > FDE mailing list > [email protected] > http://www.xml-dev.com/mailman/listinfo/fde > > > > > > > ----- Original Message ----- > From: Lark Allen > To: [email protected] > Sent: Wednesday, July 08, 2009 11:42 AM > Subject: Re: [FDE] Q concerning hardware-based encryption/security > > > Garrett, > > The alternate boot threat you describe cannot be executed against the > Seagate Momentus FDE drives. Whenever power is removed from the drive, > either at full system shutdown, or when the system goes into hibernation, the > drive locks and all user data, including the hibernation file is encrypted > and unavailable. When the system is powered up the FDE drive is locked. If > an alternate system is booted, the drive will only appear to have a 128MB > available, which is the protected read-only partition on the drive which > stores the shadow master boot record which is used to provide the pre-boot > authentication for unlocking the drive by an authorized user. Once the drive > is unlocked, then the normal boot process or return from hibernation will > execute. There is no possibility for alternate boot scenarios which will be > able to find the drive in an unlocked state. > > The Wave Embassy software you mentioned for managing the setup and security > settings for the Seagate FDE drive, forces Windows to use hibernate mode, > even if standby mode is selected by the user. In Dell systems, Seagate, > Wave, and Dell worked together to create a solution for secure standby mode, > so for Dell systems both hibernate and standby modes are supported with full > security. > > Lark Allen > > Wave Systems Corp. > From: [email protected] [mailto:[email protected]] On > Behalf Of Garrett M. Groff > Sent: Monday, July 06, 2009 11:23 AM > To: [email protected] > Subject: [FDE] Q concerning hardware-based encryption/security > > I have a concern about self-encrypting drives, specifically Seagate Momentus > FDE. While the idea looks quite brilliant, my understanding is that the user > is only prompted for credentials when booting from a cold machine (one that > has been shut down completely). If that's correct, then that presents the > following vector of attack: > > Bad Guy catches machine in standby (or hibernate?) mode. Bad Guy wakes > machine & then restarts it, booting to a USB stick (or CD) rather than the > HDD. Since HDD is already authenticated, Bad Guy mounts file system & reads > (or writes!) data directly off of HDD. > > Can someone provide technical information that confirms or denies this > potential attack vector? I'm specifically looking at Seagate's Momentus FDE > drive w/ Wave's Embassy Suite, though other vendors would logically suffer > the same vulnerability. > > Thanks. > > > > _______________________________________________ > FDE mailing list > [email protected] > http://www.xml-dev.com/mailman/listinfo/fde > > > > > > ----- Original Message ----- > From: Lark Allen > To: [email protected] > Sent: Wednesday, July 08, 2009 11:42 AM > Subject: Re: [FDE] Q concerning hardware-based encryption/security > > Garrett, > > The alternate boot threat you describe cannot be executed against the > Seagate Momentus FDE drives. Whenever power is removed from the drive, > either at full system shutdown, or when the system goes into hibernation, the > drive locks and all user data, including the hibernation file is encrypted > and unavailable. When the system is powered up the FDE drive is locked. If > an alternate system is booted, the drive will only appear to have a 128MB > available, which is the protected read-only partition on the drive which > stores the shadow master boot record which is used to provide the pre-boot > authentication for unlocking the drive by an authorized user. Once the drive > is unlocked, then the normal boot process or return from hibernation will > execute. There is no possibility for alternate boot scenarios which will be > able to find the drive in an unlocked state. > > The Wave Embassy software you mentioned for managing the setup and security > settings for the Seagate FDE drive, forces Windows to use hibernate mode, > even if standby mode is selected by the user. In Dell systems, Seagate, > Wave, and Dell worked together to create a solution for secure standby mode, > so for Dell systems both hibernate and standby modes are supported with full > security. > > Lark Allen > > Wave Systems Corp. > From: [email protected] [mailto:[email protected]] On > Behalf Of Garrett M. Groff > Sent: Monday, July 06, 2009 11:23 AM > To: [email protected] > Subject: [FDE] Q concerning hardware-based encryption/security > > I have a concern about self-encrypting drives, specifically Seagate Momentus > FDE. While the idea looks quite brilliant, my understanding is that the user > is only prompted for credentials when booting from a cold machine (one that > has been shut down completely). If that's correct, then that presents the > following vector of attack: > > Bad Guy catches machine in standby (or hibernate?) mode. Bad Guy wakes > machine & then restarts it, booting to a USB stick (or CD) rather than the > HDD. Since HDD is already authenticated, Bad Guy mounts file system & reads > (or writes!) data directly off of HDD. > > Can someone provide technical information that confirms or denies this > potential attack vector? I'm specifically looking at Seagate's Momentus FDE > drive w/ Wave's Embassy Suite, though other vendors would logically suffer > the same vulnerability. > > Thanks. > > > > _______________________________________________ > FDE mailing list > [email protected] > http://www.xml-dev.com/mailman/listinfo/fde > > > > > > _______________________________________________ > FDE mailing list > [email protected] > http://www.xml-dev.com/mailman/listinfo/fde > > > ------------------------------------------------------------------------------ > > > _______________________________________________ > FDE mailing list > [email protected] > http://www.xml-dev.com/mailman/listinfo/fde > _______________________________________________ FDE mailing list [email protected] http://www.xml-dev.com/mailman/listinfo/fde
