1. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 1ETH Zurich – Distributed Computing Group Raphael Eidenbenz, Thomas Locher, Roger Wattenhofer TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAA A A A Hidden Communication in P2P Networks Steganographic Handshake and Broadcast INFOCOM 2011

2. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 2 Spy Rendezvous In London, April’s a spring month...whereas in St.Petersburg we’re freezing our butts off. MI6 CIA

3. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 3 Spy Rendezvous In London, April’s a spring month. Yes, Russian winters are cold. Enjoy your stay, sir. ?? CIA

4. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 4 Steganographic Handshake in Networks Share files Regular peersConspirers Talk to other conspirers without raising suspicion

5. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 5 Steganographic Handshake in Networks

6. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 6 ? Steganographic Handshake in Networks

7. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 7 ? Steganographic Handshake in Networks

8. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 8 Steganographic Channels P2P File sharing –Block request sequence –Block subset selection Timing Bandwidth Ports

9. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 9 Steganographic Broadcast Send a message to all conspirers Bittorrent-like p2p file sharing system n c n-c

10. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 10 Steganographic Broadcast Send a message to all conspirers Bittorrent-like p2p file sharing system k

11. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 11 Efficient Broadcast Lemma

12. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 12 Efficient Broadcast Lemma Algorithm

13. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 13 Stronger Authority Models

14. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 14 Steganographic Handshake in BitThief BitThief is a BitTorrent client that –Free rides with BitTorrent clients [1], and –Trades tit-for-tat (T4T) with other BitThiefs [2] Block request sequence Hybrid approach using PEX –Order of peer addresses –Forged peer address [1] Locher et al., Free Riding in Bittorrent is Cheap, HotNets 2006 [2] Locher et al., Rescuing Tit-for-Tat with Source Coding, P2P 2007

15. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 15 Reprise

16. Thank You! Questions & Comments? TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAA A A A

17. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 17 References P. Erdös and A. Rényi, On Random Graphs, Publicationes Mathematicae, 1959. R. Van der Hofstad, Random Graphs and Complex Networks, 2007. BitThief – A Free Riding BitTorrent Client. http://bitthief.ethz.chhttp://bitthief.ethz.ch Locher et al., Free Riding in Bittorrent is Cheap, HotNets 2006 Locher et al., Rescuing Tit-for-Tat with Source Coding, P2P 2007

18. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 18 Encoding Bits Into a Permutation

19. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 19 Proof of Lemma 3.2

20. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 20 Broadcast under Individual Monitoring

21. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 21 Broadcast under Complete Monitoring

22. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 22 Broadcast under Stochastic Monitoring

23. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 23 Broadcast under Stochastic Monitoring

24. ETH Zurich – Distributed Computing Group Raphael Eidenbenz, INFOCOM 2011 24 Spy Rendezvous In London, April’s a spring month...whereas in St.Petersburg we’re freezing our butts off. MI6 CIA