This document discusses trusted virtual clients (TVC) as a way to address computer virus issues. TVC combines virtualization and trusted computing technologies to isolate virtual machines and enforce security policies at the virtualization layer. It allows external entities to remotely verify that only authorized code is running on each virtual machine. While virtualization helps isolate infections to individual VMs, the TVC approach adds an extra layer of protection by using a trusted platform module to measure software components and enforce access controls centrally in the virtualization layer rather than within each VM. Current TVC prototypes are based on Xen virtualization but it remains an active research area.

1. Introduction to Trusted
Virtual Client
Gustavo de Paula – gep@cesar.org.br /
gustavo.eliano@gmail.com

2. Why we are here
• Computer Virus are a big problem is the
computer industry (REF1, REF2)
– Approximately 700K virus identified in 2008
– Approximately 30% of the computers were infected
with a computer virus
– Costs of 55 billion dollars a year in US
• It would be great to let my son use my work
laptop without worrying that something would
just break!

3. How a Computer Virus Work
• Different types of virus
exists
• Compromise operating
system or some specific
application Hardware
Operating system
Applications
Virus
• Biggest problem is on the operating system infection
• Once the OS is infected, the whole computer will be
affected

4. Is there a light at the of the tunnel?
Yes!!! Virtualization

5. What is Virtualization?
• Layer between the user
OS and the hardware
• User OS can be infected
but not the virtualization
layer
• Hardware is protected
Source: http://www.cornerstone.it/solutions_server.php

6. Is virtualization the answer to all
problems?
No 
Hardware
Virtualization Layer
OS 1 OS 2
App
1.1
App
1.2
App
2.1
App
2.2
• Pros.: each VM is isolated
• Infection in one VM will not
affect the other VMs
• Cons.: Infected VM might
compromise important App data

7. How can we check if the software
components installed in a computer
were not infected?

8. • Not-for-profit organization
• Develop, define and
promote industry standards
for trusted computing
building blocks
Trusted
Computing • Computer always behave as
expected
• Allow an external entity to
remotely verify that only
authorized code is executed
• Remote Device
Attestation

9. Remote Device Attestation
• Everything starts with a TPM (Trusted Platform Module)
• TPM is used to measure all software components
• If the software components was changed its measure will be
different

10. Remote Device Attestation
• Challenger can
request an attestation
• Attestator generates
its measures and
send to challenger
• Challenger can
validate if the
measurements are
correct

11. And what about Trusted Virtual
Client???

12. TVC
Virtualization
Trusted
Computing
• Combine Virtualization and TCG technologies
• Make sure all VMs work as expected
• Allow that security policies are configured
outside each VM and are enforced by the
virtualization layer

13. Hardware
Virtualization Layer (OS)
Work VM Personal VM Network Storage Management
• Virtualization Layer
is executed on boot
• Management VM is
the main controller
• Other VMs are
started from the
management VM
• All hardware access
goes through the
virtualization layer
– Access policies
controlled

14. Access Control Defined & Enforced in
Virtualization Layer
• Runtime == Virtualization Layer
• Same approach of used by VMs
(Java, .NET)
• Each App is associated to a
access policy
• Runtime enforce policies
• Apps have NO direct access to
access control policies

15. Current TVC Status
• Virtualization is widely used in the server side
– Still starting in the client side
• There are already a lot of prototypes out there
– Citrix
– Qubes
• Most of them are based on Xen virtualization
layer
• TVC is a strong research topic in companies such
as IBM, HP and Oracle

16. Where to get more information
• Trusted Computing Group
• Xen
• Citrix Xen Client
• Trusted Computing: TCG proposals
• OpenTC Prototype
• http://en.wikipedia.org/wiki/Computer_virus
• http://technology.timesonline.co.uk/tol/news/tech_and_web/article37
21556.ece
• http://answers.google.com/answers/threadview/id/749071.html
• Trusted Virtual Platforms: A Key Enabler for Converged Client Devices,
Chris I Dalton, David Plaquin, Wolfgang Weidner, Dirk Kuhlmann, Boris
Balacheff, Richard Brown. HP Laboratories, Filton Road, Bristol

17. Thanks!