1. Security in Mobile Ad Hoc Networks
Thao p Le
Department of Computer Sciences,
Wichita State University

2. Outline of Presentation
Induction to MANET (Mobile Ad-Hoc Network)
Ad Hoc Networks Architecture
Attacks to Ad Hoc Networks
Challenge of Ad Hoc Networks
Security Solution
Conclusion

3. Introduction
Ad hoc networks are collections of mobile nodes with links that are made or broken in an arbitrary way.
No centralized controller and infrastructure.
Allows free mobility
Node acts as host and router to assist in transmitting data to other nodes in its range.
Can be quickly and inexpensively setup
Applications: military, emergency and disaster situations.

5. MANETs: Advantages
Can access information and services regardless of geographic position
Can set up computer networks at any place and time

6. Ad Hoc Networks Architecture
Rapid setup time Ad hoc mode only needs the setting up of radio network interface card (NICs) in the user devices.
Better performance possible The question of performance with ad hoc mode is certainly doubtful.
Limited network access. There is no distribution system with ad hoc wireless LANs, users don’t have effective access to the internet and other wired network services.

7. Ad Hoc Networks Architecture (cont.)
Difficult network management Network management becomes a headache with ad hoc networks because of the fluidity of the network topology and lack of a centralized device.

8. Attacks to Ad Hoc Networks
Two types of attacks target Ad Hoc network
External attacks:
MAC layer jamming
Traffic analysis
Internal attacks:
Compromised host sending false routing information
Fake authentication and authorization
Traffic flooding

9. Challenge of Ad Hoc Networks
Dynamic topology
Movement, node failure, etc.
Heterogeneous and decentralized control
Limited resources
Bandwidth, processing ability, energy
Unfriendly environment
Selfish nodes, malicious attackers

10. Challenge of Ad Hoc Networks (cont.)
Authentication and accounting
No fixed membership
Security concern
Open medium without any centralized control
Real time services
Dynamic topology and slow routing information distribution
Limited bandwidth
Congestion is typically the norm rather than the exception.

11. Problems with Security Measures
Deficiencies of intrusion prevention
Increases the overhead during normal operations of Ad Hoc networks
Restriction on power consumption and computation capability prevent the usage of complex encryption algorithms
Flat infrastructure increases the difficulty for the key management and distribution
Cannot guard against internal attacks

12. Security Solution The Multi-fence Approach in Security Solution
The proactive approach attempts to prevent security threats in the first place.
The reactive approach seeks to detect threats a posteriori (derived by reasoning from observed facts) and react accordingly. The reactive approach is widely used to protect packet forwarding operations.

13. Security Solution (cont.)
Ad hoc Secure Routing
Source Node Routing( DSR)
Distance Vector Routing (DSDV and AODV)
Link State Routing: Secure Link State Routing (SLSP)
Other Routing Protocols: ARAN

14. Conclusion
The research on MANET security is still in its early stage. The existing proposals are typically attack-oriented in that they first identify several security threats and then enhance the existing protocol or propose a new protocol to thwart such threats. Because the solutions are designed explicitly with certain attack models in mind, they work well in the presence of designated attacks but may collapse under anticipated attacks. Therefore, a more ambitious goal for ad hoc network security is to develop a multi-fence security solution that is embedded into possibly every component in the network, resulting in in-depth protection that offers multiple lines of defense against many both known and unknown security threats.

15. Sources
[1] Cavin et al., "On the accuracy of MANET simulators," Proc. ACM Workshop on Princ. Mobile Computing
[2] K.-W. Chin, et al., "Implementation Experience with MANET Routing Protocols," ACM SIGCOMM Computer Communications Review, Nov. 2002, pp Available online.
[3] Frodigh, et al, "Wireless Ad Hoc Networking: The Art of Networking without a Network," Ericsson Review, No. 4, online. [4] M. S. Corson et al., "Internet-Based Mobile Ad Hoc Networking," IEEE Internet Computing, July-August 1999
[5] C. Elliott and B. Heile, "Self-Organizing, Self-Healing Wireless Networks," Proc IEEE
[6] K. Kim, "A New Mobile Environment: Mobile Ad Hoc Networks (MANET)," IEEE
[7] C. Perkins and E Royer, “Ad Hoc On-Demand Distance Vector Routing,” 2nd IEEE Wksp. Mobile Comp. Sys.and Apps., 1999