Transcript NGSCB
The Trusted Computing (TC) and
Next Generation Secured
Computing Base (NGSCB)
Joseph Yu
Jeffrey Khuu
CS158B
Dr. Stamp
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Table of Contents
Introduction
TC
TCG
NGSCB
TC
NGSCB
Architecture
Features
Analysis of NGSCB
Summary
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Introduction – TC, TCG, NGSCB
TC = Trusted Computing, TCG = Trusted
Computing Group, NGSCB = Microsoft’s
TC
Original Motivation for TC:
TC was intended for DRM
Limits the abuse of file sharing over the network
Prevent making illegal copies without the
authorization from the vendor
Restrict user’s computing actions
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Introduction - TC
Current Motivation for TC:
“For years, Bill Gate has dreamed of finding a
way to make the Chinese pay for software: TC
looks like being the answer to his prayer.” –
Ross Anderson
TC extend way more than DRM: It gives more
authorizations to the computers over users
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Introduction - TC
Fundamental Concept of TC
Software runs and communicates securely over
applications and servers
Use “locked-down” architecture
Hardware level cryptographic keys for encryption and
authentication
Tamper-resistant
Seal secure data within curtained memory
Input/Output communication path are encrypted
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Introduction - TCG
Many vendors provide hardware support
for major components of NGSCB
For example, Intel’s LaGrande Technology (LT)
and AMD’s Secure Execution Mode (SEM)
technology
TCG is an alliance of Microsoft
Manage TC activities for different
hardware/software vendors: AMD, HP, IBM,
and others
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Introduction - TCG
Goal:
Claimed: Non-Profit industry standards
organization to enhance the security and
computing in different platforms
Provide a secured TCB for the system
Activities:
Formed in Spring 2003 and adopted a set of
specification made by Trusted Computing
Platform Alliance (TCPA)
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TC
What is Trusted Computing?
Trusted Computing Base (TCB)
TCB
“TCB is everything in operating system that we rely on
for security” Dr. Stamp
If TCB is damaged/non-secured, the whole system
broken.
If the system is broken, and TCB is ok. We still have
system security
Part of the system (combines software and hardware
components)
Responsible for regulate information security policies
Consist of Kernel, OS
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TC -- overview
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TC
Should be expected the computing behave
the way we wanted and do what we
wanted securely
Any trusted platform has the following
three fundamental features:
Protected Capabilities
Integrity Capabilities
Integrity Reporting
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NGSCB
Microsoft’s version of TC: NGSCB
Will be implemented in the upcoming
version of Windows: as known as
Microsoft Windows Longhorn
Architecture
Computing Environments
Four Features of NGSCB
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NGSCB - architecture
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NGSCB - architecture
Two primary system components in
NGSCB
Nexus
Special kernel (core of the trusted operating)
Goal: Isolate the process of normal mode and
trusted mode differently in memory
Functionality: Authenticate and protect data
(entered, stored, communicated, and displayed)
by data encryption
Nexus Computing Agent (NCA)
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NGSCB - architecture
Nexus Computing Agent (NCA)
Trusted software component
Runs in trusted mode that communicates with
Nexus
Open-source for NCA specifications
Developers can make their own agents to run
on the trusted platform
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NGSCB – Computing Environments
Overview
NSGCB operates two operating systems in ONE system
Two Modes:
Normal Mode vs. Trusted Mode
Normal Mode:
Un-protected environment
Same as our current Windows series
Fully Controlled by the users
Trusted Mode:
Protected environment
Users have no authorities to modify, delete, or copy ANY content.
Implemented TC: Hardware and Software implementation
Fully Controlled by the computers
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NGSCB – operating environments
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NGSCB – operating environments
Microsoft claimed: “Only an NGSCB
trusted application, NCA, can run securely
within the protected operating
environment.”
NCA
Defined by software developers
Policies
Security authentication
Security authorization
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NGSCB - Features
Claimed: Four Features
Strong Process Isolation
Sealed Storage
Attestation
Secured Path to the user
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NGSCB – Four Features
Strong Process Isolation
Isolate protected and non-protected operating
environment that are stored in the same
memory
Blocks the access of Direct Memory Access
(DMA) devices in term of writing and reading to
secured block of memory
Block access of malicious code
Claimed: “no illegitimate access will occurring in
protected environment”
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NGSCB – Four Features
Sealed storage
Ensure the privacy of NGSCB data are not
being exposed
NGSCB use Security Support Component (SSC)
to do this
SSC has own encryption services and can be
managed by the Nexus
Use Advance Encryption Standard (AES), pair
of public and private keys, and keys derived for
trusted application
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NGSCB – Four Features
Sealed Storage
NCA uses these keys to encrypt data, access
file system, and provide storage services.
Claimed: No unauthorized application can read
the sealed storage whatsoever (at boot up, or
running)
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NGSCB – Four Features
Cryptographic Attestation
Confirm the recipient that the data was digital
signed by the NGSCB and data was
cryptographically identifiable
Authenticates software Process
Prove application identity
Useful in networking, prove its identity securely
before transmit any data.
Avoid Man in the Middle attack?
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NGSCB – Four Features
Secure Path to the user
Ensure the information remains securely through the
input/output of the devices.
Encrypt the input/output, creates a secure path.
Protects computer from:
Keystroke recorded
Hardware devices
Need to upgrade current hardware devices:
mouse/keyboard/USB devices/ video adapter
Input: upgrade to USB devices: Smart cards, biometrics,
others
Output: upgrade to Graphic adapter, which prevent
read/write to video memory
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NGSCB Applications
Many applications involved NGSCB: regular
computing, networking, DRM, others
Example: Microsoft Word
Restrict user:
View/Copy/Write/Open/Close
Not compatible with other *.doc applications, ie.
OpenOffice
Written document is Signed and Encrypted with
Microsoft Word --- Only Word has the private key
to decrypt it
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NGSCB Application
Networking application:
Cannot file-sharing via P2P
Cannot open your friend’s packed programs
Presumably Secured with connected in network
Good for networking?
Microsoft Explorer / Outlook
User might be able to see the content but not
able to “Copy-and-Paste” to other applications
Users have no right to “do whatever they
wanted to do”
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Analysis of NGSCB
Current Problematic Computing
User can do whatever they wanted to do in
computer – taking all responsibility
Unprotected: Virus, worms, keystroke,
spywares
Abuse of file-sharing digital contents
As a conclusion, we DO need a better
computing protection operating system
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Analysis of NGSCB
Will NGSCB be the solution?
Human nature to control over things and not to
be controlled by others.
“People will not use it if it blocks and restricts
them doing what they want to do.” Quote
NGSCB will fails:
Companies will not tolerate attestations on the
network and through the firewall every time their
employee wants to open a file.
They want open the application FAST!
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Analysis of NGSCB
NGSCB will fails to work with DRM
There is always WAYS to workaround of things.
Music for example
User still can record what comes out from the
speaker, (poor quality but so what, it’s FREE)
Recorded and make MP3 out of it
Copy content for example
Take a screen shot, digital camera?
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NGSCB
As a summary of our presentation:
NGSCB will fail.
People will use alternative products:
Apple OS
Linux
Stay with Microsoft XP ??
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Q/A
Q/A
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References
[1] Mark Stamp's CS166 software presentation slides
http://www.cs.sjsu.edu/~stamp/CS166
[2] System Management Concepts: Operating system and Devices
http://www.unet.univie.ac.at/aix/aixbman/admnconc/tcb.htm
[3] TCG Specification Architecture Overview
https://www.trustedcomputinggroup.org/downloads/TCG_PCSpecificSpecification_v1_1.pdf
[4] Microsoft’s Next Generation Secured Computing Base Overview
http://www.microsoft.com/resources/ngscb/NGSCB_Overview.mspx
[5] NGSCB Security Model
http://www.microsoft.com/resources/ngscb/documents/NGSCB_Security_Model.doc
[6] Trusted Computing and NGSCB
http://www.cs.bham.ac.uk/~mdr/teaching/TrustedComputing.html
[7] Ross Anderson's Trusted Computing FAQ
http://www.cl.cam.ac.uk/~rja14/tcpa-faq.html
[8] Microsoft’s resource for NGSCB
http://www.microsoft.com/resources/ngscb/productInfo.mspx
[9] Microsoft's NGSCB four features
http://www.microsoft.com/resources/ngscb/four_features.mspx
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