RFC: Flaw in BitLocker, Apple's FileVault, TrueCrypt, and dm-crypt

http://afp.google.com/article/ALeqM5...LZudh4epei2RuQ

SAN FRANCISCO (AFP) Researchers said Friday they found a way to sidestep
encryption technology commonly used to protect sensitive data in computers.

A "major security flaw" in several types of popular encryption software
exposes supposedly safeguarded information, provided a savvy data thief can
get hold of the machines, according to the Electronic Frontier Foundation.

"People trust encryption to protect sensitive data when their computer is
out of their immediate control," said EFF staff technologist Seth Schoen, a
member of the research team.

"Whether your laptop is stolen, or you simply lose track of it for a few
minutes at airport security, the information inside can still be read by a
clever attacker."

Researchers claim they cracked an array of commonly-used encryption
programs, including Microsoft's BitLocker, Apple's FileVault, TrueCrypt, and
dm-crypt.

In a paper published on the Internet, researchers show that data is
vulnerable because encryption keys and passwords linger in the temporary
memory of computers after machines lose power.

"We discovered that on most computers, even without power applied for
several seconds, data stored in RAM seemed to remain when power was
reapplied," said research team member Jacob Appelbaum, an independent
security specialist.

"We then wrote programs to collect the contents of memory after the
computers were rebooted."

Laptops are especially vulnerable to the attack when the machines are in
lock, sleep, or hibernation modes, according to the report.

"We've broken disk encryption products in exactly the case when they seem to
be most important these days: laptops that contain sensitive corporate data
or personal information about business customers," said Princeton University
computer science doctoral student J. Alex Halderman.

"This isn't a minor flaw; it is a fundamental limitation in the way these
systems were designed."

Researchers say the attack technique is likely to be effective against many
other computer disk encryption systems because of structural similarities.

Turning laptops off completely helps guard against intrusion, but doesn't
work in all cases, according to the report.

--
Dave
http://www.claymania.com/removal-trojan-adware.html
Multi-AV - http://www.pctipp.ch/downloads/dl/35905.asp

David H. Lipman wrote:


> In a paper published on the Internet, researchers show that data is
> vulnerable because encryption keys and passwords linger in the temporary
> memory of computers after machines lose power.


I found a really bigger vulnerability: The keys are in memory while the
computer is still powered on. One could simply connect some hardware to the
memory bugs and read it out directly...
Or could could attach a key logger and wait until the user enters the
password...

> "We then wrote programs to collect the contents of memory after the
> computers were rebooted."


Only applies to hardware reboots. If the computer is properly shut down, the
software simply zeros out the key in memory.

> Laptops are especially vulnerable to the attack when the machines are in
> lock, sleep, or hibernation modes, according to the report.


Hibernate? The hibernate file is stored on the encrypted disc...

> "This isn't a minor flaw; it is a fundamental limitation in the way these
> systems were designed."


No, it's a well known intangible limit known since at least 40 years:
Software cannot defend against an attacker which has physical access to the
system.

"Sebastian G." <seppi@seppig.de> wrote in
news:62dmloF23c4ijU1@mid.dfncis.de:

....
> I found a really bigger vulnerability: The keys are in memory while
> the computer is still powered on. One could simply connect some
> hardware to the memory bugs and read it out directly...
....

The "some hardware" is already installed on many computers: Firewire. If
Firewire is enabled, the computer is on (even with keyboard locked, etc.),
and I have a few minutes access, I'm in. I can read/write all RAM - I own
the machine. It's known as the iPod/Firewire attack (for reasons I will be
happy to explain). See, for instance:
http://md.hudora.de/presentations/fi...PacSec2004.pdf

Yes, even for Windows XP (I just have to mess a little with OHCI CSRs). I

Regards,