1 / 35

The Sybil Attack, J. R. Douceur, IPTPS 2002.

The Sybil Attack, J. R. Douceur, IPTPS 2002. Clifton Forlines CSC2231 Online Social Networks 11/1/2007. Outline. Brief overview of the paper Discussion on differences between P2P networks and OSN and on how this effects Sybil attacks. “Sybil” (1973) by Flora Rheta Schreiber

onslow
Télécharger la présentation

The Sybil Attack, J. R. Douceur, IPTPS 2002.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Sybil Attack, J. R. Douceur, IPTPS 2002. Clifton Forlines CSC2231 Online Social Networks 11/1/2007

  2. Outline • Brief overview of the paper • Discussion on differences between P2P networks and OSN and on how this effects Sybil attacks

  3. “Sybil” (1973) by Flora Rheta Schreiber Attacker creates multiple identities to control a large portion of the network and overcome redundancy Sybil Attack

  4. Identity Validation • How does an entity know that two identities come from different entities? • Centralized server is one option • Douceur mentions three mechanisms of testing independence of identities in P2P • Communication • Computation • Storage

  5. Identity Validation • Four Lemmas “prove” that Sybil attacks are always possible without centralized authority

  6. Lemma 1 • Because entities are heterogeneous in terms of capabilities, a malicious entity can create several “minimal” identities • Lower-bound on number of identities

  7. Lemma 2 • Unless identities are tested simultaneously, a compromised entity can create any number of identities • Simultaneous identity verification not practical

  8. Lemma 3 • If a certain number of identities must vouch for a new identity for it to be accepted, then a set of compromised identities can create any number of new fake identities

  9. Lemma 4 • Without simultaneous validation of identities by a set of trusted entities, a single faulty entity can present many identities. • Again, simultaneous validation is difficult in real-world networks.

  10. Overview Conclusion • Networks require centralized authority to validate network identities • Without one, Sybil attacks are always a possibility

  11. Identity Validation in an OSN • Douceur mentions three mechanisms of testing independence of identities in P2P • Communication • Computation • Storage • What mechanisms exist for social networks?

  12. Identity Validation ?

  13. Identity Validation

  14. Identity Validation • OSN have lots of techniques to validate identities that are not present in P2P

  15. Network

  16. Network

  17. Network What about the links?

  18. Links in a Social Network • What are the Differences between links in a P2P network and links in an on-line social network?

  19. Links in a Social Network • What are the Differences between links in a P2P network and links in an on-line social network? • Links in OSN correspond to real-world links

  20. Links in a Social Network • What are the Differences between links in a P2P network and links in an on-line social network? • Links in OSN correspond to real-world links • Links in OSN take time and effort to setup

  21. Links in a Social Network • What are the Differences between links in a P2P network and links in an on-line social network? • Links in OSN correspond to real-world links • Links in OSN take time and effort to setup • Links in OSN cluster and have high # of intra-cluster connections

  22. Links in a Social Network • What does a link in a social network signify?

  23. Links in a Social Network • What does a link in a social network signify? • Indicates trust

  24. Links in a Social Network • What does a link in a social network signify? • Indicates trust • Vouches for individual

  25. Links in a Social Network • How many links can a malicious node in a P2P network create? • How many in an OSN?

  26. Links in a Social Network • How many links can a malicious entity in a P2P network create? • As many as one wants. (mostly) • How many in an OSN? • As many as one has time and effort to create.

  27. Network What about the links?

  28. Network

  29. Network

  30. Network

  31. Network

  32. Network

  33. How can we identify this type of edge without global network typology? Network

  34. Summary • OSN have lots of techniques to validate identities that are not present in P2P • Links in an OSN • Indicates trust • Vouches for individual • correspond to real-world links • take time and effort to setup • cluster and have high # of intra-cluster connections • Malicious entity can only create as many links as they have time and effort to create.

  35. Other Discussion Topics • IPv6 privacy (mentioned in paper)

More Related