Clustered sensor networks have been shown to increase system throughput, decrease system delay, and save energy. While those with rotating cluster heads, such as LEACH, have also advantages in terms of security, the dynamic nature of their communication makes most existing security solutions inadequate for them. In this paper, we show how random key predistribution, widely studied in the context of flat networks, can be used to secure communication in hier-archical (cluster-based) protocols such as LEACH. To our knowledge, it is the first work that investigates random key predistribution as applied to hierarchical WSNs. © 2006 IEEE.2006 145152Akyildiz, I.F., Su, W., Sankarasubramaniam, Y., Cayirci, E., A survey on sensor networks (2002) IEEE Communications Magazine, 40 (8), pp. 102-114. , AugustBohge, M., Trappe, W., An authentication framework for hierarchical ad hoc sensor networks (2003) 2005 ACM workshop on Wireless security, pp. 79-87Chan, H., Perrig, A., Song, D., Random key predistribution schemes for sensor networks (2003) IEEE Symposium on Security and Privacy (S&P'03), pp. 197-213. , mayDu, W., Deng, J., Han, Y.S., Varshney, P.K., Katz, J., Khalili, A., A pairwise key pre-distribution scheme for wireless sensor networks (2005) ACM Transactions on Information and System Security, , Also appeared in ACM CCS '03Eschenauer, L., Gligor, V.D., A key management scheme for distributed sensor networks (2002) 9th ACM conference on Computer and communications security, pp. 41-47Estrin, D., Govindan, R., Heidemann, J.S., Kumar, S., Next century challenges: Scalable coordination in sensor networks (1999) Mobile Computing and Networking, pp. 263-270. , Seattle, WA USAA. C. Ferreira, M. A. Vilaca, L. B. Oliveira, E. Habib, H. C. Wong, and A. A. F. Loureiro. On the security of cluster-based communication protocols for wireless sensor networks. In 4th IEEE International Conference on Networking (ICN'05), 3420 of Lecture Notes in Computer Science, pages 449-458, Reunion Island, April 2005Heinzelman, W.R., Chandrakasan, A., Balakrishnan, H., Energy-efficient communication protocol for wireless microsensor networks (2000) IEEE Hawaii Int. Conf. on System Sciences, pp. 4-7. , JanuaryHill, J., Szewczyk, R., Woo, A., Hollar, S., Culler, D., Pister, K., System architecture directions for networked sensors (2000) int'l Conf. on Architectural support for programming languages andoperating systems, pp. 93-104Hwang, J., Kim, Y., Revisiting random key predistribution schemes for wireless sensor networks (2004) 2nd ACM workshop on Security of ad hoc and sensor networks, pp. 43-52. , ACM PressKannan, R., Ray, L., Durresi, A., Efficient key predistribution schemes for sensor networks (2004) 1st European Workshop on Security in Wireless and Ad-Hoc Sensor Networks (ESAS'04), , Heidelberg, Germany, AugustKarlof, C., Sastry, N., Wagner, D., Tinysec: A link layer security architecture for wireless sensor networks (2004) 2nd ACM SensSys, pp. 162-175. , NovKarlof, C., Wagner, D., Secure routing in wireless sensor networks: Attacks and countermeasures (2003) Elsevier's AdHoc Networks Journal, Special Issue on Sensor Network Applications and Protocols, 1 (2-3), pp. 293-315Also appeared in 1st IEEE International Workshop on Sensor Network Protocols and ApplicationsLiu, D., Ning, P., Li, R., Establishing pairwise keys in distributed sensor networks (2005) ACM Transactions on Information and System Security (TISSEC), 8 (1). , 41-77, Also appeared in ACM CCS '03Oliveira, L.B., Wong, H.C., Loureiro, A.A.F., Lha-sp: Secure protocols for hierarchical wireless sensor networks (2005) 9th IFIP/IEEE International Symposium on Integrated Network Management (IM'05), pp. 31-44Perrig, A., Szewczyk, R., Wen, V., Culler, D., Tygar, J.D., SPINS: Security protocols for sensor networks (2002) Wireless Networks, 8 (5). , 521-534, Sept, Also appeared in MobiCom'01Pietro, R.D., Mancini, L.V., Mei, A., Random keyassignment for secure wireless sensor networks (2003) SASN '03: Of the 1st ACM workshop on Security of ad hoc and sensor networks, pp. 62-71. , New York, USASchneier, B., (1996) Applied Cryptography, , WileyWood, A.D., Stankovic, J.A., Denial of service in sensor networks (2002) IEEE Computer, 35 (10), pp. 54-62. , OctZhu, S., Setia, S., Jajodia, S., LEAP: Efficient security mechanisms for large-scale distributed sensor networks (2003) 10th ACM conference on Computer and communication security, pp. 62-72. , ACM PressZhu, S., Xu, S., Setia, S., Jajodia, S., Establishing pairwise keys for secure communication in ad hoc networks: A probabilistic approach (2003) 11th IEEE Inter'l Conference on Network Protocols (ICNP'03), pp. 326-335. , Atlanta