Trusted Computing
Platforms
Blessing or Curse?
by Bastian Sopora,
Seminar DRM 2006
Agenda
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Introduction
Defining trust and its different flavours
The idea of Trusted Computing Platforms
Technicalities of TCP
Conceptual problems with TCP
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TCP & DRM
Summary & Discussion
Introduction
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What is a Trusted Computing Platform?
Introduction
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What is a Trusted Computing Platform?
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A computer with some kind of additional hardware,
that serves to protect the system from malicious
software or unintended / undesired use.
Agenda
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Introduction
Defining trust and its different flavours
The idea of Trusted Computing Platforms
Technicalities of TCP
Conceptual problems with TCP
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
TCP & DRM
Summary & Discussion
What is trust?
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Trusted vs. Trustworthy
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The nature of trust
Technical Trust
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Computers are predictable
Trustworthy – earned trust
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User has a reason to trust in a System‘s behavior
Impossible to compromise data
 Previous behaviour and standards deserve trust
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Trusted – forced trust
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User has no other choice but to trust the system
Black box
 No alternatives
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"A 'trusted' computer does not mean a computer that is
trustworthy." – Bruce Schneier
Technical Trust
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Device does what it is supposed to do
“an entity can be trusted if it always behaves in
the expected manner for the intended purpose“
– [TCG]
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i.g. Harddrive controller
Agenda
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Introduction
Defining trust and its different flavours
The idea of Trusted Computing Platforms
Technicalities of TCP
Conceptual problems with TCP
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TCP & DRM
Summary & Discussion
Supporters
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Trusted Computing Group
Formerly known as Trusted Computing platform
alliance
 AMD, Hewlett-Packard, IBM, Infineon, Intel,
Lenovo, Microsoft, and Sun Microsystems
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TCP – pure intentions
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Make computers safer, more reliable
Protect from viruses, malware
Protect from hackers, unauthorized access
Opponents
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Computer security experts
Richard Stallman (GNU)
 Ross J. Anderson (Cambridge U., UK)
 Bruce Schneier (Comp.Sec. Author)
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TCP – not as good as it seems?
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Trust in the driving factors of TCP is
undeserved
TCP gives system and software designers too
much control and power
Undue Censorship possible
A quick survey
Who uses...
 ...AMD / Intel processors?
 ...Microsoft / Apple OS?
Think about whether you trust them or not!
Agenda
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Introduction
Defining trust and its different flavours
The idea of Trusted Computing Platforms
Technicalities of TCP
Conceptual problems with TCP


TCP & DRM
Summary & Discussion
The simple TC-life
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Trusted Platform Module
One chip solution
 Open specifications
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The TCG Guidelines
Trusted Platform Module provides:
 Secure Input & Output
 Memory curtaining / Protected execution
 Sealed storage
 Remote attestation
The Guidelines I
Secure Input & Output
 Secure channel between user and software
 Avoid keyloggers, screenparsers etc.
The Guidelines II
Memory Curtaining
 Block access to memory for all other software
 Even OS access is denied
The Guidelines III
Sealed Storage
 Encrypt files using key derived from software &
hardware
The Guidelines IV
Remote Attestation
 Certificate generated by the Trusted Platform
Module
Hardware has not been tampered with
 What software is running
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(active point of view)
Agenda
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Introduction
Defining trust and its different flavours
The idea of Trusted Computing Platforms
Technicalities of TCP
Conceptual problems with TCP


TCP & DRM
Summary & Discussion
Reflection
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What does TC do?
What could it do?
How does it work?
Additional Concepts
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Remote Attestation
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(passive point of view)
Owner Override
Remote Attestation
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What is running?
= Is XYZ running...?
...on machine UVW?
Owner Override
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Allow owner to disable functions
Allow owner to overide actions
Controversies
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Remote Censorship
Freedom of Software Choice
Limitations on Data & Information
Identifiability
TCP & Digital Licensing
Remote Censorship
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Software creators instead of users control data
objects
Data objects may be deleted without user‘s consent
 Data objects‘ distribution may be prevented
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Software Choice
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Information created with Software A may be
locked from all other software
Data Objects may require Software A although
they are of a common type
Limitations on User‘s Data
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No migration
Software requiring “newest“ software versions
Data requiring spyware
Identifiability on the Internet
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Remote Attestation
Collect information?
 Free Speech
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Direct Anonymous Attestation
Limitations on Information
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Enforcing „[Fair] Use Policy“
Limiting file formats to certain software
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Microsoft: DRM making use of TC
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TCP and Digital Licensing
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Relies on Sealed Storage & Memory Curtaining
Relies on Remote Attestation
TCP and Digital Licensing: Scenario
1
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Concept: Enforcing “[Fair] Use Policy“
Restriction of Use
Restrictions on replay
 Playability linked to user‘s behaviour
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TCP and Digital Licensing: Scenario
II
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Concept: Spyware
Marketing Trap
Evolving “[Fair] Use Policy“
Impracticality
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Constant Owner Overrides
Disabled features
Fear of control, what if...
...the controling party is ‘evil‘
 ...the hardware fails
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Frequent new developments
outdated technology
Agenda
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Introduction
Defining trust and its different flavours
The idea of Trusted Computing Platforms
Technicalities of TCP
Conceptual problems with TCP


TCP & DRM
Summary & Discussion
Survey Results
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Do you trust Intel, Microsoft, AMD, Apple etc.?
A: They pay me $$$
B: Forced Trust
C: Earned Trust
D: I don‘t use computers
Survey Results
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Do you trust Intel, Microsoft, AMD, Apple etc.?
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50/50 joker:
B: Forced Trust
C: Earned Trust
Survey Results
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Do you trust Intel, Microsoft, AMD, Apple etc.?
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Audience joker:
100
90
80
70
60
50
40
30
20
10
0
A
B
C
B: Forced Trust
C: Earned Trust
D