1. Security in Wireless Sensor Networks by Toni Farley

2. Security Concerns ©Security Concerns Defined  Integrity - Ensure that information is accurate, complete, and has not been altered in any way.  Availability - Ensure that a system can accurately perform it’s intended purpose and is accessible to those who are authorized to use it.  Confidentiality - Ensure that information is only disclosed to those who are authorized to see it. Integrity Availability Confidentiality

3. Security Concerns  Authentication – Ensure correctness of claimed identity.  Authorization – Ensure permissions granted for actions performed by entity. Authentication Authorization ICA 3

4. Points of Security Concern ©System  System Integrity  Availability ©Source  Authentication  Authorization ©Data  Data Integrity  Confidentiality WSN DataSource

5. Threats ©Authentication  Man in the middle ©Data Integrity  Modification  Forgery  Deletion  Replay ©Confidentiality  Eavesdropping

6. Wireless Security ©Magnified Threats  Detectability – Ability to discover a wireless system  Theft of Service – Unauthorized use of wireless signal  Interception – Easy to capture signals transmitted through air ©Limited Resources  Low b/w  Low memory capacity  Slow CPU  Battery Power Limits

7. Current Solution: Encryption ©Symmetric (private key) encryption  Fixed keys cannot be changed when compromised  Dynamic keys require high cost key exchange protocol  Faster algorithms – computational overhead ©Asymmetric (public/private) key encryption  Data sent to many devices must be encrypted separately with each device’s public key ©Longer keys provide better security  Longer keys require more resources, which becomes problematic if many keys are needed

8. Current Solution: Encryption ©Pretty Good Privacy (PGP)  Uses session key to encrypt data, thus only need to encrypt data one time for multiple recipients  Uses public keys to encrypt session key, requires multiple smaller encryptions  Overhead is reduced, but still exists

9. Research: SPINS ©Security Protocols for Sensor Networks [1]  Securing Node/Base Station communications  Secure Network Encryption Protocol (SNEP) 4Secure channels for confidentiality 4Data integrity through authentication 4Data freshness through partial message ordering (weak) and total order with delay estimation (strong)  micro Timed, Efficient, Streaming, Loss-tolerant Authentication Protocol (μTESLA) 4Authentication through asymmetric authenticated broadcast

10. Research: Security for Sensor Networks ©Security for Sensor Networks [2]  Securing Node/Base Station communications  Broadcasts of end-to-end encrypted packets 4Authentication 4Integrity 4Confidentiality 4Replay  Base station looks for corrupted packets or long period of inactivity 4Mechanism for detecting “bad” behavior

11. Research: Secure Routing in WSN ©Security Routing in Wireless Sensor Networks: Attacks and Countermeasures [3]  Describes routing attacks 4Known attacks 4Invented attacks 4Protocol specific attacks  Describes countermeasures for each attack 4Encryption with globally shared key 4Unique key between each node & base station 4Neighbor authentication between nodes 4Authenticated broadcast techniques

12. Security Sources ©SANS Glossary of Terms Used in Security and Intrusion Detection, http://www.sans.org/resources/glossary.php#C, May 2003. http://www.sans.org/resources/glossary.php#C ©MobileBook ©Andrew S. Tanenbaum, Computer Networks, Prentice Hall, 2003. ©Encyclopedia of Cryptography and Security, Kluwer, to be published in 2004.

13. Research References ©[1] SPINS: Security Protocols for Sensor Networks. A. Perrig, R. Szewczyk, V. Wen, D. Culler, and J. Tygar. In Seventh Annual ACM International Conference on Mobile Computing and Networks (Mobicom), 2001. ©[2] Jeffery Undercoffer, Sasikanth Avancha, Anupam Joshi, and John Pinkston, Security for Sensor Networks 2002 CADIP Research Symposium ©[3] Secure Routing in Sensor Networks: Attacks and Countermeasures, Chris Karlof and David Wagner, To appear in Elsevier's AdHoc Networks Journal, Special Issue on Sensor Network Applications and Protocols.