1. Co-opetition in Network Tasks Yoram Bachrach, Peter Key, Jeff Rosenschein, Morteza Zadimoghaddam, Ely Porat

2. Agenda Joint Network TasksAdvertising in NetworksNetwork Security

3. Negotiation 3

4. “Collective Buying Power” Quota: 100 Buyers Reward: Discount of $10 (total saving 10*100=$1000) 4 25 Users70 Users50 Users30 Users

5. Transferable Utility Games

6. Solution Concepts Cv(C) …

7. Solution Concepts Cv(C) … Stability Unblocked agreements

8. Solution Concepts Cv(C) … Fairness (Power) Average contribution across all agent permutations

9. Solution Concepts Cv(C) … Fairness (Power) Average contribution across all agent coalitions

10. Solving the Groupon Game Average contribution across all permutations Users25705030 8.33%41.67%25% Required: 100 Users 25 Users70 Users50 Users30 Users

11. Solving the Groupon Game Average contribution across all permutations Users15705030 0%66.67%16.66% Required: 100 Users 15 Users70 Users50 Users30 Users

12. Solving the Groupon Game Core: no deviations – Cannot win without the 70 users Users15705030 0%100%0% Required: 100 Users 15 Users70 Users50 Users30 Users

13. Display Advertising

14. Sponsored Search Advertising

15. Social Network Advertising

16. Social Advertising In Groupon

17. Connectivity Games s t

18. s t

19. s t

20. s t

21. s t

22. Richer Model p p p b

23. Network Reliability p p p b

24. Network Reliability Models Computer nodes (vertices) connected to each other via network links (edges) – Each link has a certain bandwidth (capacity) Within a time unit, links have a certain probability of failure – Typically networks have some redundancy Classical network reliability works – Each link has a “survival probability”, of remaining in the graph – Compute the probability of obtaining the goal in the surviving graph – Various network goals Source target connectivity (STC-P), full connectivity (FC-P), full connectivity given a backbone infrastructure, connectivity of specific servers, allowing a certain bandwidth between the source and target, … – Complexity Valiant: STC-P is #P-hard Provan and Ball: FC-P is #P hard

25. Connectivity Games p p p b

26. Example Network (1)

27. Example Network (2)

28. Hotspots and Bargaining

29. Computational Limitations CG SolutionComputation Power indices Banzhaf, Shapley #P-Complete (even without backbones) Polynomial algorithm for trees General approximations CorePolynomial algorithm Finding veto agents coNP-complete Polynomial algorithm in trees

30. Network Security Physical networks – Placing checkpoints – Locations for routine checks Computer networks – Protecting servers and links from attacks Various costs for different nodes and links – How easy it is to deploy a check point – Performance degradation for protected servers What agreements would be reached regarding related budgets and rewards?

31. Security Crowdsourcing Texas Virtual Boarder Watch – Individuals observe US-Mexico border for suspicious behavior

32. Blocking an adversary s t

33. s t

34. s t

35. s t

36. s t

37. s t

38. s t

39. Incorporating costs s t 8 2 5 3 3 2 1 2 2 7

40. s t 8 2 5 3 3 2 1 2 2 7

41. Multiple Adversaries s1 t1 8 2 5 s2 3 2 t2 2 2 7

42. Coalitions in Network Security Agents must for coalitions to successfully block the adversary – How should they split costs and rewards? Security resources are limited – Which node should be allocated these resources first? Similar tools from Game Theory s t 8 2 5 3 3 2 1 2 2 7

43. Path Disruption Games Games played on a graph G= (a network) – Simple version (PDGs): coalition wins if it can block the adversary and loses otherwise – Model with costs (PDGCs): a coalition is guaranteed a reward r for blocking the adversary, but incurs the cost of its checkpoints

44. Computational Limitations PDG SolutionComputation Coalition utility (optimal strategy)NP-Hard for multiple adversaries and costs Polynomial algorithm for other cases Power indices Banzhaf, Shapley #P-Complete even for single adversary and no costs CorePolynomial algorithm Polynomial algorithm for single adversary NP-Complete for multiple adversaries

45. Related Models Network Flow Games – C’s value: the maximal flow it can send between s and t Collusion in network auctions – Procurer buys a path from s to t in an auction – C’s value: obtained price when rigging the auction

46. Conclusions p p p b s t 8 2 5 3 3 2 1 2 2 7