By John Leyden
2nd February 2007
Security advances in Windows Vista are unlikely to frustrate cybercrime
investigation, according to a leading computer forensics firm.
Enterprise and Ultimate editions of Vista include a feature that
provides data volume encryption called BitLocker Drive Encryption.
Suggestions that BitLocker contains a backdoor allowing law enforcement
agencies automatic access to encrypted volumes have been robustly denied
But that doesn't necessarily mean the availability of Vista will mean
the widespread adoption of disc encryption technologies that will
frustrate law enforcement investigations in computer crime, including
trafficking in images of child abuse, computer hacking, industrial
espionage and other offences.
For one thing, in two of its three modes of operation BitLocker requires
a cryptographic hardware chip called a Trusted Platform Module and a
compatible BIOS. These chips are yet to become widely available much
less deployed. The third mode requires a user to insert a USB device
that contains a startup key in order to boot the protected OS.
That means law enforcement officers need to get into the habit of
seizing USB keys as well as PCs in the course of conducting a raid.
Brian Karney, director of product marketing at Guidance Software, said
the computer forensics firm had worked with Microsoft on BitLocker and
that it knew of "no backdoors".
Getting to machines while they are still turned on and taking a
forensically sound copy is an option even in the absence of USB Keys,
Karney explained. "Even though the logical volume is encrypted the OS
works on top of an abstraction layer. We can see what the OS sees so
that it's possible to acquire data on a running Vista machine even when
it is running BitLocker."
In cases when a consumer machine running Vista happens to be turned off
at the point its seized, a password is needed. However, in corporate
environments a BitLocker recovery key can be used to allow examination
of target devices.
In some ways, the issue boils down to who is more knowledgeable about
the use of encryption or other security technologies: investigators or
the targets of investigation, an issue far from restricted to use of
encryption technology in Windows Vista.
"We're seeing the same concerns with Vista as we saw with XP over the
idea that built-in encryption features might frustrate law enforcement
efforts. In practice XP has not proved to be a problem for computer
forensics and we don't think Vista will be either," said Bill Thompson,
director of professional development and training at Guidance Software.
"Sometimes people use file wiping utilities or other tools but often
they are not configured properly. People accept the default settings,
which can leave fragments of data."
Guidance Software's EnCase computer forensic software is widely used by
law enforcement agencies worldwide and is increasingly been used by
private sector firms to investigate employee wrongdoing. One of
Guidance's customers is the Metropolitan Police, which is using the
technology to recover deleted emails as part of its cash for honours
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