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

Hash graph based key predistribution scheme for mobile and multiphase wireless sensor networks

Wireless Sensor Networks (WSN) consist of small sensor nodes which operate until their energy reserve is depleted. These nodes are generally deployed to the environments where network lifespan is much longer than the lifetime of a node. Therefore, WSN are typically operated in a multiphase fashion, where new nodes are periodically deployed to the environment to ensure constant local and global network connectivity. Besides, significant amount of the research in the literature studies only static WSN and there is very limited work considering mobility of the sensor nodes. In this thesis, we present a key predistribution scheme for mobile and multiphase WSN which is resilient against eager and temporary node capture attacks. In our Hash Graph based (HaG) scheme, every generation has its own key pool which is generated using the key pool of the previous generation. This allows nodes deployed at different generations to have the ability to establish secure channels. Likewise, a captured node can only be used to obtain keys for a limited amount of successive generations. We also consider sensor nodes as mobile and use different mobility models to show its effects on the performance. We compare the connectivity and resiliency performance of our scheme with a well-known multiphase key predistribution scheme and show that our scheme performs better when the attack rate is low. When the attack rate increases, our scheme still has better resiliency performance considering that it requires less key ring size compared to a state-of-the-art multiphase scheme

Symbol Emergence in Robotics: A Survey

Humans can learn the use of language through physical interaction with their environment and semiotic communication with other people. It is very important to obtain a computational understanding of how humans can form a symbol system and obtain semiotic skills through their autonomous mental development. Recently, many studies have been conducted on the construction of robotic systems and machine-learning methods that can learn the use of language through embodied multimodal interaction with their environment and other systems. Understanding human social interactions and developing a robot that can smoothly communicate with human users in the long term, requires an understanding of the dynamics of symbol systems and is crucially important. The embodied cognition and social interaction of participants gradually change a symbol system in a constructive manner. In this paper, we introduce a field of research called symbol emergence in robotics (SER). SER is a constructive approach towards an emergent symbol system. The emergent symbol system is socially self-organized through both semiotic communications and physical interactions with autonomous cognitive developmental agents, i.e., humans and developmental robots. Specifically, we describe some state-of-art research topics concerning SER, e.g., multimodal categorization, word discovery, and a double articulation analysis, that enable a robot to obtain words and their embodied meanings from raw sensory--motor information, including visual information, haptic information, auditory information, and acoustic speech signals, in a totally unsupervised manner. Finally, we suggest future directions of research in SER.Comment: submitted to Advanced Robotic

Resilient and highly connected key predistribution schemes for wireless sensor networks

Wireless sensor networks are composed of small, battery-powered devices called sensor nodes with restricted data processing, storage capabilities. Sensor nodes collect environmental data, such as temperature, humidity, light conditions, and transmit them using their integrated radio communication interface. In real life scenarios, the exact position of a node is not determined prior to deployment because their deployment methods are arbitrary. Wireless sensor networks may be used for critical operations such as military tracking, scientific and medical experiments. Sensor nodes may carry sensitive information. In such cases, securing communication between sensor nodes becomes an essential problem. Sensor nodes may easily be impersonated and compromised by malicious parties. In order to prevent this, there is a need for some cryptographic infrastructure. Public key cryptography is infeasible for sensor nodes with limited computation power. Hence symmetric key cryptography mechanisms are applied in order to provide security foundations. Due to resource constraints in sensor nodes, best solution seems to be symmetric key distribution prior to deployment. For each node, a number of keys are drawn uniformly random without replacement from a pool of symmetric keys and loaded in the node’s memory. After deployment, neighboring sensor nodes may share a key with a certain probability since all the keys are drawn from the same key pool. This is the basic idea of key predistribution schemes in wireless sensor networks. Also there are more advanced deployment models that take the change of network in time into consideration. The nodes are powered by batteries and the batteries eventually deplete in time. However the network needs to operate longer than the lifetime of a single node. In order to provide continuity, nodes are deployed and integrated in the network at different times along the operation of the network. These networks are called multiphase wireless sensor networks. The main challenge of these networks is to provide connectivity between node pairs deployed at different times. In this thesis, we proposed three different key predistribution schemes. In the first scheme, we introduce the concept of XORed key, which is the bitwise XOR of two regular (a.k.a single) keys. Sensor nodes are preloaded with a mixture of single and XORed keys. Nodes establish secure links by shared XORed keys if they can. If no shared XORed key exists between two neighboring nodes, they try single keys loaded in their memory. If node pairs do not have any shared XORed or single keys, they transfer keys from their secure neighbors in a couple of ways, and use them to match with their XORed keys. In this scheme, we aim to have a more resilient network to malicious activities by using XORed keys since an attacker has to know either both single key operands or the XORed key itself. We performed several simulations of our scheme and compared it with basic scheme [4]. Our scheme is up to 50% more connected as compared to basic scheme. Also it has better resilience performance at the beginning of a node capture attack and when it starts to deteriorate the difference between the resilience of our proposed scheme and basic scheme is not greater than 5%. The second scheme that we proposed is actually an extension that can be applied to most of the schemes. We propose an additional phase that is performed right after shared keys between neighboring nodes are discovered. As mentioned above, neighboring node pairs share a common key with a certain probability. Obviously some neighboring node pairs fail to find any shared key. In our proposed new phase, keys preloaded in memories of secure neighbors of a node a are transferred to a, if necessary, in order for a to establish new links with its neighboring nodes that they do not share any key. In this way, we achieve the same connectivity with traditional schemes with significantly fewer keys. We compared the performance of our scheme with basic scheme [4] after shared-key discovery phase and our results showed that our scheme achieved the same local connectivity performance with basic scheme, moreover while doing that, nodes in our scheme are loaded with three fourth of keys fewer than the keys loaded in nodes in basic scheme. In addition to that, our scheme is up to 50% more resilient than basic scheme with shared-key discovery phase under node capture attacks. The last scheme that we proposed is designed to be used for multi-phase wireless sensor networks. In our model, nodes are deployed at the beginning of some time epochs, called generations, in order to replace the dead nodes. Each generation has completely different key pool. Nodes are predistributed keys drawn uniformly random from key pools of different generations in order to have secure communication with nodes deployed at those generations. In other words, in our scheme keys are specific to generation pairs. This makes the job of attacker more difficult and improves the resiliency of our scheme. We compared our scheme to another key predistribution scheme designed for multi-phase wireless sensor networks. Our results showed that our scheme is up to 35% resilient in steady state even under heavy attacks

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

Self-Healing Polymer Composites for Structural Application

Self-healing materials are the next-generation materials for high-performance structures. To reduce the fatigue and subsequent probability of failure along with extended service life of polymer and polymer composites, the self-healing concept has great potential. Today, polymeric composites are structural matrix and prone to failure against cyclic mechanical and thermal loading. Significant degradation of polymeric structures at surficial sites can be measured by barely visible impact damage (BVID), but internal micro-cracks are not easily detectable. Various damage modes make major damage sites in composites and further lead to catastrophic failure of the structure. On-site repairing of microscopic or macroscopic damages in polymer composites is a value-added function that is offered by self-healing techniques. Different extrinsic methods including encapsulation, hollow fiber embedment, and vascular methods are preferred, and some intrinsic, dynamic bonding is created by reversible covalent networks and supramolecular interaction based on H-bonding, metal-ligand, and ionomers. This chapter is preferred on the new trends and challenges regarding the structural health monitoring of polymeric composites against external mechanical and environmental impacts and extended service life and performance by utilizing self-healing strategies

Application of software and hardware-based technologies in leaks and burst detection in water pipe networks: a literature review

With the rise of smart water cities, water resource management has become increasingly important. The increase in the use of intelligent leak detection technologies in the water, gas, oil, and chemical industries has led to a significant improvement in safety, customer, and environmental results, and management costs. The aim of this review article is to provide a comprehensive overview of the application of software and hardware-based technologies in leak detection and bursts in water pipeline networks. This review aims to investigate the existing literature on the subject and to analyse the key leak detection systems in the water industry. The novelty of this review is the comprehensive analysis of the literature on software and hardware-based technologies for leak and burst detection in water pipe networks. Overall, this review article contributes to understanding the latest developments and challenges in the application of software- and hardware-based technologies for leak and burst detection in water pipe networks, and serves as a valuable resource for researchers, engineers, and practitioners working in the field of water distribution systems

Micro/nanofluidic and lab-on-a-chip devices for biomedical applications

Micro/Nanofluidic and lab-on-a-chip devices have been increasingly used in biomedical research [1]. Because of their adaptability, feasibility, and cost-efficiency, these devices can revolutionize the future of preclinical technologies. Furthermore, they allow insights into the performance and toxic effects of responsive drug delivery nanocarriers to be obtained, which consequently allow the shortcomings of two/three-dimensional static cultures and animal testing to be overcome and help to reduce drug development costs and time [2–4]. With the constant advancements in biomedical technology, the development of enhanced microfluidic devices has accelerated, and numerous models have been reported. Given the multidisciplinary of this Special Issue (SI), papers on different subjects were published making a total of 14 contributions, 10 original research papers, and 4 review papers. The review paper of Ko et al. [1] provides a comprehensive overview of the significant advancements in engineered organ-on-a-chip research in a general way while in the review presented by Kanabekova and colleagues [2], a thorough analysis of microphysiological platforms used for modeling liver diseases can be found. To get a summary of the numerical models of microfluidic organ-on-a-chip devices developed in recent years, the review presented by Carvalho et al. [5] can be read. On the other hand, Maia et al. [6] report a systematic review of the diagnosis methods developed for COVID-19, providing an overview of the advancements made since the start of the pandemic. In the following, a brief summary of the research papers published in this SI will be presented, with organs-on-a-chip, microfluidic devices for detection, and device optimization having been identified as the main topics.info:eu-repo/semantics/publishedVersio

Advanced Battery Technologies: New Applications and Management Systems

In recent years, lithium-ion batteries (LIBs) have been increasingly contributing to the development of novel engineering systems with energy storage requirements. LIBs are playing an essential role in our society, as they are being used in a wide variety of applications, ranging from consumer electronics, electric mobility, renewable energy storage, biomedical applications, or aerospace systems. Despite the remarkable achievements and applicability of LIBs, there are several features within this technology that require further research and improvements. In this book, a collection of 10 original research papers addresses some of those key features, including: battery testing methodologies, state of charge and state of health monitoring, and system-level power electronics applications. One key aspect to emphasize when it comes to this book is the multidisciplinary nature of the selected papers. The presented research was developed at university departments, institutes and organizations of different disciplines, including Electrical Engineering, Control Engineering, Computer Science or Material Science, to name a few examples. The overall result is a book that represents a coherent collection of multidisciplinary works within the prominent field of LIBs