19th October 2004

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(No Transcript)
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19th October 2004 Regional Blackouts
Protection of Broadcast Content on 3G
Networks Alexander W. Dent Allan Tomlinson,
Information Security Group, Royal Holloway,
University of London
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Introduction

• Motivation
• Collaboration between broadcast and mobile
  networks
• Potential to deliver broadcast content over 3G
  networks
• Potential issues with content protection
• Digital Rights Management (DRM)
• Ownership of Content
• Distribution Rights
• Licensing

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Background

• Regional Blackouts
• Broadcast Content subject to restrictions
• Geographical
• In the region around a stadium where a live event
  is taking place
• Time
• During the time when a live event takes place
• Immediately after the event

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Background

• Current Solutions
• Conditional Access systems
• Scrambled content
• Regional codes
• Embedded in receivers
• Entitlement management
• Descrambling authorised according to regional
  codes
• Broadcast time controlled by broadcaster

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Background
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Background

• Mobile Receivers
• Current solutions assume
• Relatively static receivers
• Broadcaster controls play-out and billing
• Mobile receivers
• No longer static
• Content forwarding

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Background
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New Problem

• Content Provider may trust broadcaster to control
  distribution to initial receiver
• Content Provider cannot trust initial receiver to
  control further distribution
• Further distribution is controlled by the user
• End Device can be any IP enabled device
• End Device may be completely controlled by user
• Impact on future mobile services

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Potential Solutions

• Trusted Hardware
• Insist on trusted hardware on End Device
• Install GPS on end device
• Expensive
• Trusted Network
• Network provides time and location data
• End Device must be connected directly to network
• Secure Protocols

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Network Model
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Assumptions

• STB and ED have a secure execution environment
  and a tamper-proof data storage area
• All cryptographic processing on STB and ED is
  carried out in the secure execution environment
• Only applications running in the secure execution
  environment have access to the tamper-proof data
  storage areas in the STB and the ED
• At least one authenticated key, K, is shared by
  STB and ED and is stored in the tamper-proof data
  storage areas

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Assumptions

• At least one of the ED or STB possesses a public
  verification transform, VCA, for a certification
  authority CA, stored in its tamper-proof data
  storage area
• At least one of the ED or STB possesses a DRM
  application stored in its tamper-proof data
  storage area
• At least one of the ED or STB has knowledge of
  the usage criteria for each service received

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Protocol 1
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Protocol 1

• Advantages
• Simple
• Disadvantages
• Heavy computational load on the intermediary
  network.
• Heavy computational load on the end device (which
  may have limited computational power)
• Trust in DRM application on the end device

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Protocol 2
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Protocol 2

• Advantages
• Simple
• Low computational load for the end device
• Good source of nonces from scrambled broadcasts
• Most DRM performed on STB, less trust in ED
• Disadvantages
• Still heavy computational load on the
  intermediary network

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Conclusions

• Protocols deliver secure time and location
  information from mobile devices to DRM
  applications.
• Computational load on intermediary network.
• Potential for Denial of Service attacks

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Thank you ! For further information
please contact Dr. Allan Tomlinson E-mail
allan.tomlinson_at_rhul.ac.uk Tel 44 (1784)
414346 WWW www.mobilevce.com