1. The Holey Grail A special score function for non-binary traitor tracing Boris Škorić Jan-Jaap Oosterwijk Jeroen Doumen

2. Piracy Copy protection Illegal or unofficial copy Traitor tracing 20-11-2013 / Department of Mathematics & ComputerScience PAGE 1

3. Traitor Tracing 20-11-2013 / Department of Mathematics & ComputerScience PAGE 2 User ID...

4. Collusion Compare several watermarked copies Locate the differences Create new watermark 20-11-2013 / Department of Mathematics & ComputerScience PAGE 3 Ingrid... Pierre... Travis... New

5. Collusion-Resistant Traitor Tracing 20-11-2013 / Department of Mathematics & ComputerScience PAGE 4 0.90.80.10.4... Ingrid... Pierre... Travis... New...

6. Collusion-Resistant Traitor Tracing (II) Compare the collusion watermark to all user watermarks Attribute a level of suspicion to each user Accuse users that are too suspicious 20-11-2013 / Department of Mathematics & ComputerScience PAGE 5

7. Level of suspicion 20-11-2013 / Department of Mathematics & ComputerScience PAGE 6 0 guilty innocent level of suspicion FNFP accusation threshold

8. Code length 20-11-2013 / Department of Mathematics & ComputerScience PAGE 7

9. Nice properties Level of suspicion of innocent users Zero mean (independent of collusion strategy) Unit variance (independent of collusion strategy) Level of suspicion of coalition Mean is independent of collusion strategy 20-11-2013 / Department of Mathematics & ComputerScience PAGE 8

10. Larger alphabets Using larger alphabets allows for better schemes. 2011, Boesten et al.: Fingerprinting capacity increases 2013, Oosterwijk et al.: Capacity-achieving scheme But... mean level of suspicion of coalition does depend on the collusion strategy 20-11-2013 / Department of Mathematics & ComputerScience PAGE 9

11. Traitor Tracing Scheme 20-11-2013 / Department of Mathematics & ComputerScience PAGE 10

12. The Grails 20-11-2013 / Department of Mathematics & ComputerScience PAGE 11

13. Holy Grail 20-11-2013 / Department of Mathematics & ComputerScience PAGE 12

14. Holey Grail 20-11-2013 / Department of Mathematics & ComputerScience PAGE 13

15. Conclusion Collusion-Resistant Traitor Tracing Scheme Level of suspicion of innocent users Zero mean (independent of collusion strategy) Unit variance (independent of collusion strategy) Level of suspicion of coalition Mean is independent of collusion strategy Possible for non-binary alphabets, but this construction performs worse than was hoped. 20-11-2013 / Department of Mathematics & ComputerScience PAGE 14

16. Thanks for your attention! Questions?

17. EURASIP Journal on Information Security Topics are among others o Collusion Secure Fingerprinting codes o Transactional Watermarking and Traitor Tracing o Collusion Secure Watermarking o Transactional Watermarking and Fingerprinting for data sets / sets of files o Real World reports or experiences or insights regarding the legal perspective http://jis.eurasipjournals.com/ Guest-editors: Boris Škorić, Eindhoven Univ. of Tech. Jan-Jaap Oosterwijk, Eindhoven Univ. of Tech. Thijs Laarhoven, Eindhoven Univ. of Tech. Jeroen Doumen, Irdeto BV Waldemar Berchtold, Fraunhofer Institute SIT Martin Steinebach, Fraunhofer Institute SIT Marcel Schäfer, Fraunhofer Institute SIT Editor-in-Chief: Stefan Katzenbeisser, TU-Darmstadt CfP: Special Issue on Collusion Secure Fingerprinting and Transactional Watermarking Deadline for submissions, February 28, 2014