On the Key Revocation Schemes in Wireless Sensor Networks Dieynaba Mall and Karim Konaté Department of Mathematics and Computer Science Université Cheikh Anta Diop de Dakar Dakar, Senegal dieynaba.mall@ucad.edu.sn, karim.konate@ucad.edu.sn Al-Sakib Khan Pathan Department of Computer Science International Islamic University Malaysia Kuala Lumpur, Malaysia sakib@iium.edu.my Abstract—Among all security issues, key management is the most attractive mechanism to ensure security of applications and network services in wireless sensor networks. Key management includes two important aspects namely: Key distribution, which constitutes the task of distributing secret keys to nodes in the network and Key revocation, which refers to the task of securely withdrawing the key information relating to any compromised network node. While in the literature, key distribution has been extensively studied; key revocation has received relatively little attention. In this paper, we present a survey on the state-of-the-art key revocation techniques and also present the security and performance analysis that highlights the advantages and disadvantages of each scheme. Keywords—Key; Management; Revocation; Security; Sensor; Wireless I. INTRODUCTION A wireless sensor network (WSN or simply, sensor network throughout this paper) is a specialized ad hoc network composed of a large number of low cost and limited-power sensor nodes. It is designated to perform a wide variety of missions that are difficult for humans to carry out. Due to the insecure nature of the wireless communication medium and dynamic changes of the network topology, WSNs are vulnerable to a wide range of attacks and are thus difficult to secure. In addition to this, because of the constrained nature of sensors in a WSN, usually being limited in energy and computing power as well as their field of application, security issues in such a network must be carefully carried out. Cryptographic techniques are essential to guaranty the security services such as confidentiality, integrity, and authentication and to resist against the increasing number of attacks. Thus, an effective management of cryptographic keys is always required to provide communication security in sensor networks. Generally a WSN is designed for deployment in open, in an unmonitored environment, thus exposing nodes to physical attacks. Any key management solution in WSNs must then be provided with the ability to revoke the cryptographic keys of captured nodes. Otherwise, the entire network’s operation could be compromised by adversaries. We seek to provide a better understanding of the current research issues related to the revocation problem in WSNs. To do so, we present a survey on the state-of-the-art techniques and highlight the advantages and disadvantages of various schemes. Moreover, we compare and evaluate these solutions based on each of the two categories of the schemes. The remainder of this paper is organized as follows: in section II, we review the solutions related to the issue of key revocation in sensor networks, followed by a security and performance analysis in section III. This paper is finally concluded in Section IV. II. REVOCATION SCHEMES IN WIRELESS SENSOR NETWORKS In wireless sensor networks, revocation schemes can be categorized as either centralized or distributed, depending on the level of involvement of a designated centralized authority. A. Definitions and Notations The major terms used in this paper are defined as follows:  Neighboring node – is a node located within the communication range of a given node;  Target node – is the node to be revoked in the revocation process;  Participant – any node sharing a pairwise key with the target node is a participant. We can distinguish two categories of participants depending on their proximity to the target node. 1. Local participant – which is a neighboring node of the target node ; 2. Non-local participant – which is a node located at greater distance;  Local neighborhood Broadcast – is a broadcast limited to the neighborhood of a given node. More specifically, this refers to a multi-hop broadcast that originates within a given neighborhood and attains all the nodes inside that neighborhood;  Centralized authority – is an entity sharing a pairwise key with every network node and which is responsible for conducting the centralized revocation of any node in 2013 IEEE International Conference on Green Computing and Communications and IEEE Internet of Things and IEEE Cyber, Physical and Social Computing 978-0-7695-5046-6/13 $26.00 © 2013 IEEE DOI 10.1109/GreenCom-iThings-CPSCom.2013.66 290