1An Efficient and Scalable Key Management
Mechanism for Wireless Sensor Networks
Walid Abdallah*, Noureddine Boudriga*, Daehee Kim**, and Sunshin An**(*)Communication Networks and Security research Lab, University of Carthage, Tunisia;(**) Computer Network research Lab, Department of Electronics Engineering, Korea University, Seoul, Korea
Abstract—A major issue to secure wireless sensor networks is key distribution. Current key distribution schemes are not fully adapted to thetiny, low-cost, and fragile sensors with limited computation capability, reduced memory size, and battery-based power supply. This paper
investigates the design of an efficient key distribution and management scheme for wireless sensor networks. The proposed scheme can ensure
the generation and distribution of different encryption keys intended to secure individual and group communications. This is performed basedon elliptic curve public key encryption using Diffie-Hellman like key exchange and secret sharing techniques that are applied at different levelsof the network topology. This scheme is more efficient and less complex than existing approaches, due to the reduced communication andprocessing overheads required to accomplish key exchange. Furthermore, little number of keys with reduced sizes are managed in sensor nodes
which optimizes memory usage, and enhances scalability to large size networks.
Index Terms—Wireless sensor networks, Security, Elliptic curve cryptography, Key management.

Walid Abdallah: is an Assistant Professor at the aviation school of Borj Elamri, Tunisia. He received his PhD in Informationand communication technologies and the Diploma of engineer in telecommunications from the School of Communications
engineering (Sup’Com), Tunisia. He received his Master Diploma from the National School of Engineer of Tunis (Tunisia).
From 2001 to 2005 he worked for the National Digital Certification Agency (NDCA, Tunisia) and from 1997 to 2001 heworked for the national telecommunication operator (Tunisia Telecom). Currently, he is a member of the Communication
Networks and Security Lab, where he is conducting research in optical networks and wireless sensor networks.

Noureddine Boudriga is an internationally known scientist/academic. He received his PhD in algebraic topology fromUniversity Paris XI (France) and his PhD in computer science from the University of Tunis (Tunisia). He is currently a fullProfessor of Telecommunications at the University of Carthage, Tunisia and the Director of the Communication Networks andSecurity Research Laboratory (CNAS). He has served as the General Director and founder of the Tunisian National Digital
Certification Agency. He is the recipient of the Tunisian Presidential award in Science and Research (2004). He was involvedin very active research and authored and co-authored many journal papers, book chapter, and books on networks and security.

Daehee Kim received the B.S. degree in Electronics Engineering from Yonsei University, Korea, in 2003 and M.S. degree inElectronic and Computer Engineering from Korea University, Korea, in 2006. Currently, he is working for Ph.D. degree on
Electronic and Computer Engineering in Korea University, Korea. His research interests include the wireless sensor network,LTE, and security in wireless networks.

SunshinAn received the B.S. degree from Seoul National University, Korea in 1973, and the M.S. degree in ElectricalEngineering from KAIST (Korea Advanced Institute of Science and Technology), Korea in 1975 and the Ph.D. degree inElectric and Information from ENSEEIHT, France in 1979. He joined the faculty of Korea University in 1982, where he iscurrently a Professor of Electronic and Computer Engineering. Prior to joining Korea University, Prof. An was AssistantProfessor of Electronic Engineering in Ajou University, Suwon, Korea. He was with NIST (National Institute of Standardsand Technology) in U.S.A., as a visiting scientist in 1991. His research interests include the distributed system,
communication networks and protocols, information network, intelligent network, multimedia communication system,
wireless sensor network and mobile RFID network