Wireless Sensor Network is a class of wireless ad hoc networks. Self organization is an important phase of a wireless sensor network. After deployment, sensors nodes are required to self organize themselves to form a network of their own. Security is an important aspect while forming the network. Only the authorized nodes should be allowed to join the network. For implementing security, such as confidentiality, integrity and authentication, keys are needed. How keys are handled is described in key management approach. Key management encompasses generation, storage, distribution, re-key and retirement of a key. It is observed that majority of the attacks are carried out during the key distribution phase itself. Hence, a proper key management is utmost important for implementing fool proof security in a Wireless Sensor Network. Depending upon the type of keys used, for example, symmetric or asymmetric key, key management techniques vary. In this paper an approach to key management for asymmetric key based security schemes of Wireless Sensor Network is proposed. The approach considers entire life of a ‘key’ and subsequently proposes algorithms/schemes for key (pre) distribution, re-key and revocation. We also discuss security planning steps for wireless sensor network in this paper.

1. Amin, F., Jahangir, A. H., and Rasifard, H. Analysis of public-key cryptography for wireless sensor networks security. World Academy of Science, Engineering and Technology 41 (2008).
2. Bertoni, G., Breveglieri, L., and Venturi, M. Power aware design of an elliptic curve coprocessor for 8 bit platforms. Proceedings of the Fourth Annual IEEE International Conference on Pervasive Computing and Communications Workshops (PERCOMW_S06) (2006).
3. Camtepe, S. A., and Yener, B. Combinatorial design of key distribution mechanisms for wireless sensor networks.
4. Camtepe, S. A., and Yener, B. Key distribution mechanisms for wireless sensor networks: a survey. Tech. Rep. TR-05-07, Rensselaer Polytechnic Institute, Computer Science Department, Lally 310, 110 8th Street, Troy, NY 12180-3590. 2005.
5. Chang, J.-H., and Tassiulas, L. Maximum lifetime routing in wireless sensor networks. IEEE/ACM Transactions on Networking (TON) Volume 12, Issue 4 (2004).
6. D Chorzempa, M. W. Key management for wireless sensor networks in hostile environments. Master's thesis, Virginia Polytechnic Institute and State University, 2006.
7. Dressler, F. Key management in wireless sensor networks.
8. Du, W., Wang, R., and Ning, P. An efficient scheme for authenticating public keys in sensor networks. MobiHoc_S05, May 25} U27, Urbana Champaign, Illinois, USA (2005).
9. Goulet, W. Summarizing pki certificate validation, 2009.
10. Gupta, V., Wurm, M., Zhu, Y., Millard, M., Fung, S., Gura, N., Eberle, H., and Shantz, S. C. Sizzle: A standards-based end-to-end security architecture for the embedded internet. SMLI TR-2005-145 (2005).
11. Haque, M. M., Pathan, A.-S. K., Hong, C. S., and Huh, E.-N. An asymmetric key-based security architecture for wireless sensor networks.
12. Hu, W., Corke, P., Shih, W. C., and Overs, L. secfleck: A public key technology platform for wireless sensor networks.
13. Jing, Q., Hu, J., and Chen, Z. C4w: An energy efficient public key cryptosystem for large-scale wireless sensor networks. vol. Oct. 2006 Page(s):827 - 832, Mobile Adhoc and Sensor Systems (MASS), 2006 IEEE International Conference on.
14. Kalita, H. K., and Kar, A. A new algorithm for end to end security of data in a secure self organized wireless sensor network. Journal of Global Research in Computer Science ISSN 2229-371X 1, 3 (November 2010).
15. R. Watro, D. Kong, S. fen Cuti, C. Gardiner, C. Lynn, and P. Kruus. Tinypk: Securing sensor networks with public key technology. In 2nd ACM workshop on Security of adhoc and sensor networks SASN, 2004.
16. X. Du and H.-H. Chen. Security in wireless sensor networks. IEEE Wireless Communications, 2008.

WSN Security Key Management PKI Digital Certificate Digital Signature