Presenter: Sandeep Mapakshi CS 6910-ACIS – Project 6 Instructor: Prof. Leszek T. Lilien, Fall 2006

1. Rushing Attacks and Defense in Wireless Ad Hoc Network Routing ProtocolsYih-Chun Hu, Adrian Perrig, and David B. Johnson Presenter: Sandeep Mapakshi CS 6910-ACIS – Project 6 Instructor: Prof. Leszek T. Lilien, Fall 2006 Department of Computer Science Western Michigan University

2. Outline • On-Demand Routing Protocols • Rushing Attacks • Rushing Attack Prevention • Evaluation • Conclusion

3. Introduction • Wireless Ad hoc network • a collection of mobile computers (or nodes) cooperate to forward packets • dynamic topology • self-organization

4. Introduction (cont.) • Routing protocol • Transport Subsystem • Neighbor State Maintenance • Database Maintenance • Ad hoc network routing protocols • Run in untrusted environments • Provide resilience against misconfigured nodes

5. Routing Protocols • Proactive routing protocol • Table-Driven routing protocol • Reactive routing protocol • Source-Initiated On-Demand routing protocol • Forward ROUTE REQUEST packets when needed

6. Comparison between Table-Driven Routing and On-Demand Routing On-demand Routing Table-driven Routing Immediately from Route Table Availability of Routing information After Route discovery When requested Periodic advertisements Route updates Proportional to number of communication nodes and increase with increased node mobility Proportional to size of network regardless of network traffic Routing overhead

7. A-B-D-G A-B-D-G A-B-D-G A-B A A-B-D A-C-E A A-C-E A-C-E A-C On-Demand Route Discovery B G Destination D A source H E C F

8. The Rushing Attack • On-demand routing protocols use duplicate suppression at each node: first ROUTE REQUEST that reaches a node is considered legitimate, next are discarded (all have the same identifier, higher identifiers denote new requests) • Attacker scatters RREQ quickly throughout the network suppressing any later legitimate RREQ • Initiator will be unable to discover any usable routes containing at least two hops • An effective denial-of-service attack

9. Why is the Attack Possible? • An attacker can send faster, by avoiding the delays that are part of the design of both routing and MAC (802.11b) protocols. • Why Delay in ROUTE REQUEST forwarding ? • In a MAC protocols using time division • On-demand protocols generally specify a delay • Remove these delays at both the MAC and routing layers? - more collisions • Attacker can send at a higher wireless transmission level • An attacker can take advantage of a wormhole, to create flood rushing attacks, use the wormhole to rush the packets ahead of the normal flow

10. Rushing Attack D S Slide courtesy: [2]

11. Rushing Attack Example • A sends a ROUTE REQUEST

12. Rushing Attack Example • A sends a ROUTE REQUEST • B forwards the REQUEST without checking the signature, or otherwise rushes the REQUEST

13. Rushing Attack Example • A sends a ROUTE REQUEST • B forwards the REQUEST without checking the signature, or otherwise rushes the REQUEST • C correctly processes the REQUEST, and forwards it later as a result

14. Rushing Attack Example • A sends a ROUTE REQUEST • B forwards the REQUEST without checking the signature, or otherwise rushes the REQUEST • C correctly processes the REQUEST, and forwards it later as a result • Since D has already heard a REQUEST from this discovery, D discards the REQUEST

15. Rushing Attack Example • B rushes the REQUEST • C forwards it later • Since D has already heard a REQUEST from this discovery, D discards the REQUEST • A discovers a path through B because B rushed the REQUEST

16. Rushing Attack Example Route discovery process under no attack B C Route Query A E Route Query Route Query Route Reply D

17. Rushing Attack Example Route discovery process under attack Attacker Attacker B C Route Query Route Reply A E Route Query Route Query D

18. Wormhole Attack • Attacker records a packet at one location in the network, tunnels the packet to another location. • Packets may be replayed from the far end of the wormhole. • Puts attacker in a powerful position. • It’s a replay so authentication does not help Applications of the Wormhole Attack • Denial-of-Service • Routing Disruptions • Unauthorized Access

19. Routing Tree Adapted from Chris Karlof and David Wagner's WSNPA slides

20. Routing Adapted from Chris Karlof and David Wagner's WSNPA slides

21. Wormhole Attack • Tunnel packets received in one place of the network and replay them in another place • The attacker can have no key material. All it requires is two transceivers and one high quality out-of-band channel Adapted from Chris Karlof and David Wagner's WSNPA slides

22. Disrupted Routing • Most packets will be routed to the wormhole • The wormhole can drop packets or selectively forward packets to avoid detection Adapted from Chris Karlof and David Wagner's WSNPA slides

23. What Protocols Are Vulnerable? • On-demand unsecure (AODV, DSR) and secure (ARAN, Ariadne, etc) protocols • Result: when under attack, the routing protocol will not be able to discover paths longer than 2 hops

24. Network Assumption • Network links are bidirectional • Ignore unidirectional links • Ignore jamming attack • Requires additional hardware • Easier to detect • Disregard attacks on MAC protocol • MAC (Medium Access Control) • ALOHA and Slotted ALOHA • Medium-sized • 50～500 nodes • Clustering

25. Security Assumptions And Key Setup • Fast authentication protocol • Instantly-verifiable broadcast authentication • Keys setup • Broadcast authentication key are distributed in advance • Powerful attacker • Coordinated attacker

26. yes Single-Hop? Gather n REQUESTS; Randomly Choose 1 Secure Neighbor Detection Original Routing Protocol no Secure Routing Requirements And Protocol • Secure Neighbor Detection • Secure route delegation • Randomized ROUTE REQUEST forwarding

27. Secure Neighbor Detection • Neighbor Detection • Two nodes detect a bidirectional link between themselves • In Proactive routing protocol • In Reactive routing protocol • Requirements • Sender-receiver can check that the other is within the normal communication range • Node needs to hear Neighbor Request

28. Secure Neighbor Detection • Three-round mutual authentication protocol • S broadcasts a Neighbor Request packet • R return a Neighbor Reply packet to S • S sends a Neighbor Verification to B • Short delay timing • Within a maximum communication range sender receiver neighbor Request broadcast neighbor reply neighbor verfication

29. Notation

30. Secure Neighbor Detection (cont.) • Nonces η1,η2 • freshness <M2,ΣM2> <M3,ΣM3> R1 <M1,ΣM1> S R2

31. Secure Neighbor Detection (cont.) • Integration with an On-Demand Protocol • A＊: REQUEST || Neighbor RequestA • BA: Neighbor ReplyBA || Neighbor RequestB • AB: Neighbor VerificationAB || Neighbor ReplyAB • B＊: REQUEST || Neighbor VerificationAB || Neighbor VerificationBA

32. Secure Route Delegation • Delegate neighbor to forward the Route Request packet • To verify that both nodes of each adjacent node pair indeed believes to be a neighbor • A received ROUTE REQUESTSR || id • MA =<Route Delegation,A,B,S,R,id>ΣMA=Sign(H(MA))AB: <ΣMA>

33. Randomized Message Forwarding • To minimize the chance that a rushing adversary can dominate all returned routes • Randomized message forwarding • Collects a number of REQUESTs • Selects a REQUEST at random to forward • The number of REQUEST packets collected • The more the better? • The algorithm by which timeouts are chosen • Topology closer • Geographically closer • Randomly

34. Secure Route Discovery • To secure any protocol using an on-demand Route Discovery protocol • Secure Neighbor Detection • Secure route delegation • Randomized ROUTE REQUEST forwarding • To limit the number of REQUESTs that traverse an attacker • The nodes that don’t have n distinct path to the source of the REQUEST • Choose a random timeout • Two addition security optimizations • Each REQUEST signed • Use location information

35. Evaluation • Simulation Evaluation • Underlying protocol: Adriane • HORS as broadcast signature • 100 nodes • 1000 m x 1000 m • Random waypoint model • Pause Time: 0, 30, 60, 120, 300, 600, 900 • Workload: 5 flows • 4 packets per second • 64-byte packets

36. Packet Delivery Ratio • % of Offered traffic • DSR • 99.8% to 100% • Ariadne • 95% to 100% • RAP • 7.6% to 47.7% • MAC-layer congestion Slide courtesy: [2]

37. Median Latency • DSR and Ariadne • zero mean latency • RAP • Congestion • Waiting to forward a REQUEST Slide courtesy: [2]

38. Packet Overhead • 5 flows has 5x as much overhead • Reduces usefulness • Overhead should reduce when congestion not an issue Slide courtesy: [2]

39. Overall • Evaluation • RAP adds significant costs • Higher costs due to congestion at lower bit rates. • RAP is designed to be used only when necessary • Only when underlying protocol is unable to discover a working route • Security Analysis • Attacker needs to propagate ROUTE REQUEST from each ROUTE DISCOVERY from many locations. • Wouldn’t do it if they considered due to intrusion detection

40. Conclusion • Described the Rushing attack • Presented RAP (Rushing Attack Prevention) • RAP incurs higher overhead, but it can find usable routes when other protocols cannot work

41. References • [1]Yih-Chun Hu,Adrian Perrig, David B.Johnson , “Rushing attacks and defense in wireless ad hoc network routing protocols”, Proceedings of the 2003 ACM workshop on Wireless security, San Diego, CA, USA. Available at: http://www.ece.cmu.edu/~adrian/projects/secure-routing/wise2003.pdf • [2] Rushing Attacks and Defense in Wireless Ad Hoc Network Routing Protocols Yih-Chun Hu, Adrian Perrig, and David B. Johnson Presenter: Tammy Nguyen. Available at: http://www.eecs.wsu.edu/~smedidi/teaching/Spring05/rushing1.ppt