Trust

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Trust Digital Rights Management

• DIEHL Eric
• Security Technology Director
• CESAR 2008, 5 December

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Trust
Trust No One
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Outline

• Trust your model
• Trust your implementation
• Trust the greed

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Trust your model
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Trust model
OpenSSL
Alice
Bob
Eve
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Trust model for DRM
DRM
Alice
Bob
Eve
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What does it mean?

• Worst scenario!
• The attacker fully controls the host
• This is also true in game consoles
• Secure coding techniques
• Will TPM bring some help?
• Law 1 Attackers will always find their way
• Is Open source DRM possible?
• C2C
• Trusted partners

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Trust model for a new breed DRM
Clear content DRM
Alice
Bob
Authority
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What does it mean?

• Serious privacy issue
• Monitor what you watch
• Till to proof the business viability

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Real world model
Alice
Bob
Ruth
Eve
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Trust your implementation
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Compliance Robustness Regimes
Trust model
What do we trust
Compliance rules
What does it have to do
Robustness rules
What does it have to resist
Means for compliance
How we force it to comply
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Tools?

• Secure implementations
• How to test them?
• Basic tools for testing typical exploits
• Key management, side channel attacks, buffer
  overflow
• Robustness
• How to resist to attacks?
• Does it respect the trust model?
• Does it respect the robustness rules?

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Trust the greed
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Economic incentives

• Some failures
• AACS and PowerDVD
• Selling hardware and not content
• Align incentives!
• The entity that implements security must suffer
  from eventual loss.

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How to solve?

• Study the economics
• Return On Investment
• Return On Non Loss
• Take into account psychology
• Prospect Theory
• Use game theory
• Adjust parameters or scenarii to get win-win Nash
  equilibrium
• Adjust business models correspondingly

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An example DRM and game theory
DRM
Pay
No DRM
Steal
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Conclusions

• Trust is paramount for DRM
• Suitable Trust Model
• Trust of implementation
• Fields of research
• Trust model for attacker owned platform
• Tools to check implementation
• Use economics and psychology in design of global
  system

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Thank you for your attention
This document is for background informational
purposes only. Some points may, for example, be
simplified. No guarantees, implied or otherwise,
are intended