Abstract-In this paper, we present a trust establishment and management framework for hierarchical wireless sensor networks. The wireless sensor network architecture we consider consists of a collection of sensor nodes, cluster heads and a base station arranged hierarchically. The framework encompasses schemes for establishing and managing trust between these different entities. We demonstrate that the proposed framework helps to minimize the memory, computation and communication overheads involved in trust management in wireless sensor networks. Our framework takes into account direct and indirect (group) trust in trust evaluation as well as the energy associated with sensor nodes in service selection. It also considers the dynamic aspect of trust by introducing a trust varying function which could be adjusted to give greater weight to the most recently obtained trust values in the trust calculation. The architecture also has the ability to deal with the inter-cluster movement of sensor nodes using a combination of certificate based trust and behaviour based trust. Wireless sensor networks help to accurately gather information, monitor and react to events from the physical world. A sensor node consists of sensor(s), wireless communication device, small microcontroller and energy source. WSNs have certain unique characteristics at both the sensor node level and the sensor network level. At the sensor node level, each sensor node has constraints on resources such as energy, memory, computation speed and bandwidth. At the sensor network level, WSNs may inherit the infrastructureless nature of the wireless ad hoc networks, and they can have dynamic network topology and membership, without the support of a management authority. In addition, WSNs may be deployed in large scale and can be mobile but can suffer from the lack of physical protection, as well as general failures that relate at the node and communication level. WSNs have many applications such as surveillance of infrastructure, habitat monitoring, health care and traffic control. Many applications of the WSNs require secure communications and quality of service [1] . But in practice, wireless sensor networks are prone to different types of malicious attacks, such as denial of service, routing protocol attacks as well as replay attacks, sybil attacks, traffic analysis and physical attacks on nodes. Traditional cryptoschemes may not prevent such types of malicious attacks. Moreover, traditional trust management schemes developed for wired and wireless networks may not be suitable for networks with small sensor nodes due to limited bandwidth and stringent node constraints in terms of power and memory. Therefore, it is important to develop trust management schemes and protocols that take into account the intrinsic features of wireless sensor networks mentioned above. There are several proposals for trust management for WSNs Recently, Shaikh et al [8] have proposed a group-based trust management scheme (GTMS) for clustered wireless sensor networks. It is aimed to detect and prevent selfish, faulty and malicious nodes. However, it does not take into account the dynamic aspects of trust and predeployment knowledge of sensor nodes. Moreover, GTMS has significant communication overhead in terms of calculations needed to determine a node's trust value. We have recently proposed a trust management architecture for hierarchical WSNs in order to remedy some of the shortcomings of GTMS [9] . This paper builds on the new trust management framework for WSNs proposed in [9] , aiming to improve the trust evaluation process by taking into account the dynamic aspects of trust. Our new trust management framework makes use of the hierarchical wireless sensor network architecture to minimize the memory overhead by using the cluster head in the management of trust information. Our approach also reduces the communication overhead by making the nodes only communicate with the cluster head. We propose a novel trust value calculation scheme with a decaying technique, so that recent trust values could be given more (or less) weight in the overall trust calculation, thereby taking into account the dynamic nature of trust. The bad behavior of a node will reduce its trust value greatly. In addition, the weighting is parameterized to make it flexible enough to suit various applications. We also take into account the energy level of sensor nodes to avoid the short life time of highly trustworthy nodes. Moreover, we envisage that the nodes may move from one cluster to another, while maintaining their trust records. Furthermore, we strengthen the cluster head security. Finally, we combine the behaviour based trust and certificate based trust using pre-deployment
Zhang et al. REF proposed a dynamic trust establishment and management framework, and a trust varying function is defined to generate certain weight value for adapting to the dynamic changes of the network.
A Dynamic Trust Establishment and Management Framework for Wireless Sensor Networks
2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing
2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing
Computer Science