19 th October 2004 Regional Blackouts: Protection of Broadcast Content on 3G Networks

2. 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

3. 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

4. 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

5. 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

6. Background

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

8. Background

9. 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

10. 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

11. Network Model

12. 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

13. 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

14. Protocol 1

15. 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

16. Protocol 2

17. 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

18. 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

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