From: GPCG Talk List [mailto:[EMAIL PROTECTED] On 
> Behalf Of Horst Herb
> Sent: Friday, 22 October 2004 9:53 AM
> To: [EMAIL PROTECTED]
> Subject: [GPCG_TALK] Virtual Privacy Machine
> 
> The seems to resolve many of our security problems arising 
> from inadequate choices of software and operating system: 
> http://pvpm.metropipe.net/
> 
> I will review it and comment when I am finished, but this 
> looks like something EXTREMELY promising, and might even be 
> expanded to a complete electronic heath record system on a 
> USB stick (not just the data, but the software to view and 
> modify the health records as well)

Yes, this is extremely clever and extremely interesting. The innovative part
is that it does not require you to reboot the computer into which you plug
the USB memory stick. Instead, it loads a CPU emulator (they use QEMU) under
the currently running operating system - Windows or Linux - and then boots a
completely separate Linux operating system inside the emulator. This
emulated Linux environment is configured to only store data on the USB
memory stick, so there is no danger of inadvertently leaving
security-sensitive data on the host machine which may be your computer, or
it may be someone else's computer.

This has several implications:

A) It provides an excellent environment for accessing privacy-sensitive Web
sites, such as one's bank accounts, or one's Web-based HER. It is a much
under-appreciated fact that the biggest security vulnerability with
Web-based applications is the client-side browser and all the information it
leaves behind, such as cache files, cookies, stored passwords and other
automatic form fill-ins. Things like Google Desktop Search (see
http://desktop.google.com/ ) now make it incredibly easy to access all this
stored-or-captured but not-directly-visible information.

If you always use the same computer, and you are the only person to use that
computer, none of this matters too much, but that situation is quite rare.
At the very least, every computer is in some danger of being lost or stolen
at some stage. Yes, you can use an encrypting filesystem to protect every
file stored on a machine, but how many of us actually do that?

Up until now, it has been possible to use a bootable Linux distribution like
Knoppix or one of its many derivatives to overcome this problem, by storing
all data on removal media like a USB memory stick. Knoppix provides
excellent facilities for doing this, including encryption of the entire data
partition on the USB stick. However, the need to reboot into the Knoppix or
similar environment is often inconvenient - you need to close what you are
doing, and if it is not your computer, the owners often get a worried look
on their faces when they see a strange version of Linux booting on their
machine. This Virtual Privacy Machine overcomes these objections.

B) PKI key generation, storage and use. There have been two broad choices
for the generation, storage and handling of PKI keys and certificates until
now:

i) generation, use and storage of the keys/certificates on a general purpose
computer - thus exposing the private keys to possible compromise via all the
security holes and flaws present in general purpose computers used for
everyday things.

ii) Generate, store and process the private keys/certificates on a device
which has an embedded processor and special-purpose operating system and
software (typically a dongle, memory card or stick) - all access is via an
API, and private keys are never transferred to the host computer. Typically
a password is also needed to unlock the private keys on the cryptographic
hardware module. Disadvantages of this approach include the cost of the
special-purpose hardware device, and the fact that they are proprietary,
which means you must trust the manufacturer to have gotten everything right
- and there are several examples where this has not be the case.

However, this Virtual Privacy Machine seems to offers an interesting middle
path between the two: two-factor security due to the physical device (the
USB memory stick) which one must possess, as well as a password to unlock
it; and, as the name implies, a virtual private environment in which to do
cryptographic and other processing - sure you are still using the host
computer's CPU - but nothing else - in particular you are not using (and
thus having to trust) the host computer's operating system or other files,
and you are not using its hard disc.

The real advantage is that the hardware part is a commodity item - any USB
memory stick will do - and these are now very cheap -  as opposed to a
proprietary cryptographic device which tends to be expensive due to their
low volume. Add to that the open source nature of the software components,
and the fact that the system is far more general-purpose than a
cryptographic device, and it has to be a winner.

I think that government agencies and other organisations which are promoting
both Web-based access to privacy-sensitive EHRs by health professionals and,
most importantly, by patients, should look into this project and invest in
its further development. Likewise, government agencies and other
organisations which are promoting PKI regimes for use by health professional
and agencies should look into this project and invest in its further
development as a cheaper, more flexible alternative to proprietary
cryptographic devices, and as a more secure alternative to "soft
certificates" or keys store on PC hard disks.

Tim C


> 
> Horst
> 

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