Key management for wireless sensor network security

Wireless Sensor Networks (WSNs) have attracted great attention not only in industry but also in academia due to their enormous application potential and unique security challenges. A typical sensor network can be seen as a combination of a number of low-cost sensor nodes which have very limited computation and communication capability, memory space, and energy supply. The nodes are self-organized into a network to sense or monitor surrounding information in an unattended environment, while the self-organization property makes the networks vulnerable to various attacks.Many cryptographic mechanisms that solve network security problems rely directly on secure and efficient key management making key management a fundamental research topic in the field of WSNs security. Although key management for WSNs has been studied over the last years, the majority of the literature has focused on some assumed vulnerabilities along with corresponding countermeasures. Specific application, which is an important factor in determining the feasibility of the scheme, has been overlooked to a large extent in the existing literature.This thesis is an effort to develop a key management framework and specific schemes for WSNs by which different types of keys can be established and also can be distributed in a self-healing manner; explicit/ implicit authentication can be integrated according to the security requirements of expected applications. The proposed solutions would provide reliable and robust security infrastructure for facilitating secure communications in WSNs.There are five main parts in the thesis. In Part I, we begin with an introduction to the research background, problems definition and overview of existing solutions. From Part II to Part IV, we propose specific solutions, including purely Symmetric Key Cryptography based solutions, purely Public Key Cryptography based solutions, and a hybrid solution. While there is always a trade-off between security and performance, analysis and experimental results prove that each proposed solution can achieve the expected security aims with acceptable overheads for some specific applications. Finally, we recapitulate the main contribution of our work and identify future research directions in Part V

Dynamic keyring update mechanism for mobile wireless sensor networks/

Wireless Sensor Networks (WSNs) are composed of small, battery-powered devices called sensor nodes. Sensor nodes have sensing, processing and communication capabilities to monitor the environment and gather data. WSNs have various application areas ranging from military surveillance to forest fire detection. Security is an important issue for Wireless Sensor Networks because sensor nodes are deployed in hostile and unattended areas. Nodes are vulnerable to physical capture attacks and the attackers can easily eavesdrop on network communications. To provide security to WSNs, many key predistribution schemes have been proposed. However, most of these schemes consider the static WSNs and they perform poorly when they are applied to Mobile Wireless Sensor Networks (MWSNs). In this thesis, we propose Dynamic Keyring Update (DKRU) mechanism for MWSNs. The aim of DKRU mechanism is to enable sensor nodes to update their keyrings periodically during movement, by observing the frequent keys in their neighbors. Our mechanism can be used together with different key predistribution schemes and it helps to increase the performance of them. For performance evaluation reasons, we used our mechanism together with an existing random key predistribution scheme and a location-based key predistribution scheme. For each of these key predistribution schemes, we analyzed our mechanism using two different mobility models. Our results show that DKRU mechanism increases the local and global connectivity when it is applied to MWSNs. Moreover, our mechanism is scalable and it does not cause significant degradation in network resiliency and communication overhead

Hierarchical Grid-Based Pairwise Key Pre-distribution in Wireless Sensor Networks

The security of wireless sensor networks is an active topic of research where both symmetric and asymmetric key cryptography issues have been studied. Due to their computational feasibility on typical sensor nodes, symmetric key algorithms that use the same key to encrypt and decrypt messages have been intensively studied and perfectly deployed in such environment. Because of the wireless sensor's limited infrastructure, the bottleneck challenge for deploying these algorithms is the key distribution. For the same reason of resources restriction, key distribution mechanisms which are used in traditional wireless networks are not efficient for sensor networks. To overcome the key distribution problem, several key pre-distribution algorithms and techniques that assign keys or keying material for the networks nodes in an offline phase have been introduced recently. In this paper, we introduce a supplemental distribution technique based on the communication pattern and deployment knowledge modeling. Our technique is based on the hierarchical grid deployment. For granting a proportional security level with number of dependent sensors, we use different polynomials in different orders with different weights. In seek of our proposed work's value, we provide a detailed analysis on the used resources, resulting security, resiliency, and connectivity compared with other related works.Comment: 13 pages, 9 figures, 2 tables, to appear in the International Journal of Networks and Securit

An efficient approach of secure group association management in densely deployed heterogeneous distributed sensor network

A heterogeneous distributed sensor network (HDSN) is a type of distributed sensor network where sensors with different deployment groups and different functional types participate at the same time. In other words, the sensors are divided into different deployment groups according to different types of data transmissions, but they cooperate with each other within and out of their respective groups. However, in traditional heterogeneous sensor networks, the classification is based on transmission range, energy level, computation ability, and sensing range. Taking this model into account, we propose a secure group association authentication mechanism using one-way accumulator which ensures that: before collaborating for a particular task, any pair of nodes in the same deployment group can verify the legitimacy of group association of each other. Secure addition and deletion of sensors are also supported in this approach. In addition, a policy-based sensor addition procedure is also suggested. For secure handling of disconnected nodes of a group, we use an efficient pairwise key derivation scheme to resist any adversary’s attempt. Along with proposing our mechanism, we also discuss the characteristics of HDSN, its scopes, applicability, future, and challenges. The efficiency of our security management approach is also demonstrated with performance evaluation and analysis

A key distribution scheme tailored for mobile sensor networks

Wireless Sensor Networks, (WSN), are composed of battery-powered and resource-limited small devices called sensor nodes. WSNs are used for sensing and collecting data in the deployment area to be relayed to a Base Station (BS). In order to secure WSNs, first of all key distribution problems must be addressed. Key distribution problem is extensively studied for static WSNs, but has not been studied widely for mobile WSNs (MWSN). In this thesis, we proposed key distribution mechanisms for MWSNs. We propose a scheme in which both sensor nodes and the BS are mobile. In our scheme, the BS works as a key distribution center as well. It continuously moves in the environment and distributes pairwise keys to neighboring sensor nodes. In this way, the network gets securely connected. We conduct simulations to analyze the performance of our proposed scheme. The results show that our scheme achieves a local connectivity value of 0.73 for half-mobile network scenario and 0.54 for fully-mobile network scenario. These values can be further improved by using multiple BSs or increasing the speed of the BS. Moreover, our scheme provides perfect resiliency; an adversary cannot compromise any additional links using the captured nodes. We also incorporate two well-known key distribution mechanisms used for static networks into our scheme and provide a better connectivity in the early stages of the sensor network. The improvement in local connectivity, however, comes at the expense of reduced resiliency at the beginning. Nevertheless, the resiliency improves and connectivity converges to our original scheme's values in time