A high performance and intrinsically secure key establishment protocol for wireless sensor networks Ali Fanian a,⇑ , Mehdi Berenjkoub a , Hossein Saidi a , T. Aaron Gulliver b a Department of Electrical and Computer Engineering Isfahan University of Technology (IUT) Isfahan, Iran b Department of Electrical and Computer Engineering University of Victoria Victoria, BC Canada article info Article history: Received 1 April 2010 Received in revised form 16 December 2010 Accepted 25 January 2011 Available online 11 February 2011 Responsible Editor: J. Misic Keywords: Wireless sensor networks Key management Network security Random key pre-distribution Symmetric polynomials Deployment knowledge abstract Key establishment among neighboring sensors is the most challenging issue for security services such as authentication and confidentiality in wireless sensor networks (WSNs). Many key establishment schemes have recently been proposed, but most have security or performance issues. In this paper, we propose a novel key establishment protocol which is suitable for low resource sensor nodes. In this protocol, each sensor has a secret key and some common keys with other sensors. A common key between two sensors is generated using the secret of one sensor and the identity of the other. This key is stored in one of the sensors, and the other sensor generates it when a secure connection is required. We develop the proposed protocol for different key distribution models. These models use pre-deployment knowledge to distribute the common keys among sensors. The proposed scheme is analyzed based on connectivity, scalability, memory consumption and resistance against attacks. In comparison with previous approaches, the proposed protocol is the most resilient against compromised node attacks. In addition, it has low memory requirements and low computational overhead. Crown Copyright Ó 2011 Published by Elsevier B.V. All rights reserved. 1. Introduction Wireless sensor networks usually comprise a number of sensors with limited resources. Each sensor includes sens- ing equipment, a data processing unit, a short range radio device and a battery [1–3]. These networks have been con- sidered for various purposes including border security, military target tracking and scientific research in danger- ous environments [4–6]. Since the sensors may reside in an unattended and/or hostile environment, security is a critical issue. An adversary could easily access the wireless channel and intercept the transmitted information, or dis- tribute false information in the network. Under such cir- cumstances, authentication and confidentiality should be used to achieve network security. Since authentication and confidentiality protocols require a shared key between entities, key management is one of the most challenging issues in wireless sensor networks (WSNs) [4]. In the literature, key management protocols are based on either symmetric or asymmetric cryptographic func- tions [4]. Due to resource limitations in the sensors, key management protocols based on public keys are not suit- able [4,8]. Hence, key management protocols based on symmetric cryptographic functions have been extensively investigated [8–29]. There are two types of symmetric key management schemes based on an on-demand trust center or key pre-distribution. With an on-demand trust center, the center must generate common keys for every pair of nodes that wish to establish a secure connection. Due to the lack of an infrastructure in WSNs, this scheme is not suitable. With key pre-distribution, key material is distributed among all nodes prior to deployment. In this scheme, each node carries a set of keys to establish a se- cure connection with other nodes. 1389-1286/$ - see front matter Crown Copyright Ó 2011 Published by Elsevier B.V. All rights reserved. doi:10.1016/j.comnet.2011.01.016 ⇑ Corresponding author. E-mail addresses: Fanian@ec.iut.ac.ir (A. Fanian), Brnjkb@cc.iut.ac.ir (M. Berenjkoub), hsaidi@cc.iut.ac.ir (H. Saidi), agullive@ece.uvic.ca (T. Aaron Gulliver). Computer Networks 55 (2011) 1849–1863 Contents lists available at ScienceDirect Computer Networks journal homepage: www.elsevier.com/locate/comnet