The new and upcoming field of wireless sensor networking is unfortunately still lacking in terms of both digital forensics and security. All communications between different nodes (also known as motes) are sent out in a broadcast fashion. These broadcasts make it quite difficult to capture data packets forensically and, at the same time, retain their integrity and authenticity. The study presents several attacks that can be executed successfully on a wireless sensor network, after which the dissertation delves more deeply into the flooding attack as it is one of the most difficult attacks to address in wireless sensor networks. Furthermore, a set of factors is presented to take into account while attempting to achieve digital forensic readiness in wireless sensor networks. The set of factors is subsequently discussed critically and a model is proposed for implementing digital forensic readiness in a wireless sensor network. The proposed model is next transformed into a working prototype that is able to provide digital forensic readiness to a wireless sensor network. The main contribution of this research is the digital forensic readiness prototype that can be used to add a digital forensics layer to any existing wireless sensor network. The prototype ensures the integrity and authenticity of each of the data packets captured from the existing wireless sensor network by using the number of motes in the network that have seen a data packet to determine its integrity and authenticity in the network. The prototype also works on different types of wireless sensor networks that are in the frequency range of the network on which the prototype is implemented, and does not require any modifications to be made to the existing wireless sensor network. Flooding attacks pose a major problem in wireless sensor networks due to the broadcasting of communication between motes in wireless sensor networks. The prototype is able to address this problem by using a solution proposed in this dissertation to determine a sudden influx of data packets within a wireless sensor network. The prototype is able to detect flooding attacks while they are occurring and can therefore address the flooding attack immediately. Finally, this dissertation critically discusses the advantages of having such a digital forensic readiness system in place in a wireless sensor network environment. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Computer Science / unrestricted

A Wireless Sensor Network (WSN) is a dense network of autonomous devices (or motes) with sensors that cooperatively monitor some physical or environmental conditions. These devices are resource constrained -limited memory, power and computational resources. Thus, any algorithm developed for WSN should be deigned such that the algorithm consumes the resources as minimal as possible. The problem addressed in this thesis is developing a low-complexity algorithm for intrusion detection in the presence of clutter arising from moving vegetation, using Passive Infra-Red (PIR) sensors. The algorithm is based on a combination of Haar Transform (HT) and Support-Vector-Machine (SVM) based training. The spectral signature of the waveforms is used to separate between the intruder and clutter waveforms. The spectral signature is computed using HT and this is fed to SVM which returns an optimal hyperplane that separates the intruder and clutter signatures. This hyperplane obtained by offline training is used online in the mote for surveillance. The algorithm is field-tested in the Indian Institute of Science campus. Based on experimental observations about the PIR sensor and the lens system, an analytical model for the waveform generated by an intruder moving along a straight line with uniform velocity in the vicinity of the sensor is developed. Analysis on how this model can be exploited to track the intruder path by optimally positioning multiple sensor nodes is provided. Algorithm for tracking the intruder path using features of the waveform from three sensors mounted on a single mote is also developed.

This thesis investigates the problem of detecting an intruder in the presence of clutter in a Passive Infra-Red (PIR) based Wireless Sensor Network (WSN). As one of the major objectives in a WSN is to maximize battery life, data transmission and local computations must be kept to a minimum as they are expensive in terms of energy. But, as intrusion being a rare event and cannot be missed, local computations expend more energy than data transmission. Hence, the need for a low-complexity algorithm for intrusion detection is inevitable. A low-complexity algorithm for intrusion detection in the presence of clutter arising from wind-blown vegetation, using PIR sensors is presented. The algorithm is based on a combination of Haar Transform (HT) and Support Vector Machine (SVM) based training. The amplitude and frequency of the intruder signature is used to differentiate it from the clutter signal. The HT was preferred to Discrete Fourier Transform (DFT) in computing the spectral signature because of its computational simplicity -just additions and subtractions suffice (scaling coefficients taken care appropriately). Intruder data collected in a laboratory and clutter data collected from various types of vegetation were fed into SVM for training. The optimal decision rule returned by SVM was then used to separate intruder from clutter. Simulation results along with some representative samples in which intrusions were detected and the clutter being rejected by the algorithm is presented. The implementation of the proposed intruder-detection algorithm in a network setting comprising of 20 sensing nodes is discussed. The field testing performance of the algorithm is then discussed. The limitations of the algorithm is also discussed. A closed-form analytical expression for the signature generated by a human moving along a straight line in the vicinity of the PIR sensor at constant velocity is provided. It is shown to be a good approximation by showing a close match with the real intruder waveforms. It is then shown how this expression can be exploited to track the intruder from the signatures of three well-positioned sensing nodes.

Les Réseaux de Capteurs Sans Fil (RCSF ou Wireless Sensor Network - WSN) sont l'une des technologies les plus importantes du 21ème siècle. La plupart des chercheurs et les analystes estiment que, dans un proche avenir, ces micro-capteurs seront intégrés partout dans l’environnement de notre vie quotidienne. Ces dernières années, l'Internet des Objets (Internet of Things - IoT) est également une des technologies émergentes qui se développe rapidement. Deux nouveaux standards permettent de déployer des réseaux sans fil de faible consommation énergétique connectés à internet : le protocole 6LowPAN (Low power Wireless Personal Area Networks) qui permet notamment d’apporter l’adressage IPv6 aux capteurs grâce à l’encapsulation et la compression des données et le protocole de routage RPL (IPv6 routing protocol for low-power and lossy network) qui permet à l’information de circuler dans les WSN de proche en proche à un faible coût énergétique. Bien que le développement de ces techniques soit extrêmement rapide, plusieurs problèmes causés principalement par le manque de ressources des micro-capteurs (puissance limitée de traitement, problèmes de bande passante et de connexion des liens avec perte de données, problème de ressource énergétique limitée) demeurent et doivent être résolus, notamment pour les applications agro-environnementales. / The wireless sensor network (WSN) is one of the most important technologies of the 21st century. Most researchers and technical analysts believe that in the near future, these micro-sensors will be integrated into the environment of our daily lives. In recent years, the IoT (Internet of Things) and WoT (Web of Things) technologies also have great forwarding. Especially, the IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) protocol has allowed the use of IPv6 protocol stack in the field of WSN, thanks to its encapsulation and compression mechanisms in IPv6 packet header. Moreover, the RPL (IPv6 Routing Protocol for Low-power and Lossy Network) provides such a powerful routing function that can be applied for a variety of application scenarios. These two key standards of IoT and WoT technologies for WSN can be used in an IPv6 stack, and they will successfully achieve the connection between Internet and micro-sensors. Thus, due to the availability of IPv6 address (128-bit), all the communicating objects, such as smart device, sensor, and actuator, can be connected to the Internet. That is the greatest advantage brought by the IoT. Although the progress of these techniques is extremely fast, several issues caused by resource constraints of micro-sensor (limited processing power, bandwidth and lossy connection link, and energy), such as QoS, energy efficient, robustness and lifetime of WSN, and the most important, the special requirement of agricultural applications. Notice that Precision Agriculture is are still very challenging and waiting to be solved. Essentially, these open questions would dabble in the aspects like telemedicine, remote home automation, industrial control etc. Thus, the results obtained in this work will have a significant impact on both economic and scientific. Economically, it can offer a solution for WSN to support sustainable development in the field of agriculture automation. While scientifically, we will contribute to the routing protocol standardization of wireless micro-sensors in the domain of environmental monitoring.

The objective of this thesis is to get familiar with wireless sensor networks technologies and with standard IEEE 802.15.4. and communication principle in wireless sensor networks built on this standard. Main goal of this project is to design a packet analyzer, which is capable to catch data on chosen channel and this data is able to analyze. Part of this project is production of necessary microcontroller software equipment. Another output of this project is do a research of available packet analyzers on market and compare them with analyzer build by this thesis.

This master's thesis deals with the idea of using mobile devices as sensor nodes in wireless sensor network. Focused mostly on Android platform, we explore possibilities of wireless communication, and describe various types of sensors on mobile devices. We design and implement wireless sensor network based on mobile devices running Android operating system. The network performs real-time capturing of data from all sensors available and optionally from GPS. All measurements are visualized at the base station, which is Java Standard Edition desktop application. Wi-Fi, Bluetooth or even cellular internet can be used for communication within the network. Nodes can be remotely configured via SMS messages.

A wireless sensor network consists of small, limited-resource embedded systems exchanging environment data and activating controls. These networks can be deployed in hostile environments to monitor wildlife habitats, implemented in factories to locate mobile equipment, and installed in home environments to optimize the use of utilities. Each of these scenarios requires network security to protect the network data. The IEEE 802.15.4 standard is designed for WSN communication, yet the standard states that it is not responsible for defining the initialization, distribution, updating, or management of network public keys. Individuals seeking to research security topics will find that there are many 802.15.4-compliant development hardware kits available to purchase. However, these kits are not easily compared to each other without first-hand experience. Further, not all available kits are suitable for research in WSN security. This thesis evaluates a broad spectrum of 802.15.4 development kits for security studies. Three promising kits are examined in detail: Crossbow MICAz, Freescale MC1321x, and the Sun SPOT. These kits are evaluated based on their hardware, software, development environment, additional libraries, additional tools, and cost. Recommendations are made to security researchers advising which kits to use depending on their design needs and priorities. Suggestions are made to each company on how to further improve their kits for security research.

With the rapid development of the Internet of Things, Wireless Sensor Networks (WSNs) are deployed increasingly all over the world, providing data that can help increase sustainable development. Currently in Uppsala, Sweden, the GreenIoT project monitors air pollution by using WSNs. The resource constrained nature of WSNs demand that special care is taken in the design of communication models and communication protocols. The publish-subscribe (pub/sub) model suits WSNs very well since it puts an intermediary the broker server between sensor nodes and clients, thus alleviating the workload of the sensor nodes. The IETF (Internet Engineering Task Force) is currently in the process of standardizing a pub/sub extension to the Constrained Application Protocol (CoAP). Since the extension is such a recent addition to CoAP and not yet standardized, there are very few actual implementations of it and little is known of how it would work in practice. The GreenIoT project is considering replacement of their current pub/sub broker with the CoAP pub/sub broker since its underlying implementation is likely to be more energy efficient and the standardizing organization behind CoAP is the well-esteemed IETF. On a general level, this report offers an investigation of the problems and challenges faced when implementing the CoAP pub/sub extension with respect to design choices, implementation and protocol ambiguities. More specifically, a CoAP pub/sub broker is implemented for the GreenIoT project. By means of carefully analyzing the CoAP protocol and CoAP pub/sub draft as well as other necessary protocols, then proceeding to make decisions of what programming language to use as well as what existing CoAP library to use, a broker server was implemented and tested iteratively as the work proceeded. The implementation gave rise to several questions regarding the pub/sub draft which are also discussed in the report. / Den hastiga utvecklingen av Sakernas Internet över hela världen har medfört ett ökat användande av trådlösa sensornätverk vars datainsamling kan bidra till en mer hållbar utveckling. För närvarande använder sig GreenIoT-projektet i Uppsala av trådlösa sensornätverk för att övervaka halterna av luftföroreningar. Resursbegränsningarna för dylika nätverk medför att särskild hänsyn måste tas vid design av såväl kommunikationsmodeller som kommunikationsprotokoll. Modellen Publicera-Prenumerera (pub/pre) passar ypperligt för trådlösa sensornätverk då en mellanhand placeras mellan klient och server en s.k. broker vilket får den positiva effekten att att sensornoderna avlastas. För närvarande är IETF (Internet Engineering Task Force) i färd med att standardisera en pub/pre-utvidgning av det redan standardiserade CoAP (Constrained Application Protocol). Eftersom att utvidgningen är så pass ny finns ytterst få implementationer av den och man vet därmed väldigt lite om hur den faktiskt fungerar i praktiken. GreenIoT-projektet överväger att ersätta sin nuvarande pub/pre-broker med en CoAP pub/pre-broker eftersom att energianvändningen kan antas bli lägre samt att standardiseringsorganisationen bakom CoAP är det välrenommerade IETF. Sett ur ett större perspektiv erbjuder denna rapport en undersökning av de problem och utmaningar man ställs inför vid implementation av CoAP pub/pre-utvidgningen med avseende på designval, implementationsval, och protokolltvetydigheter. Mer konkret implementeras en CoAP pub/pre-broker åt GreenIoT-projektet. Genom att först noggrant analysera CoAP-protokollet, CoAP pub/pre-utkastet, liksom andra nödvändiga protokoll, för att därefter bestämma vilket programmeringsspråk och vilket existerande CoAP-bibliotek som skulle användas, implementerades en broker server som testades iterativt under processens gång. Ett flertal frågor som uppstod rörande pub/pre-utkastet presenteras och diskuteras i rapporten.

Factory shop floors of the future will see a significant increase in interconnected devices for monitoring and control. However, if a Service Orientated Architecture (SOA) is implemented on all such devices then this will result in a large number of permutations of services and composite services. These services combined with other business level components can pose a huge challenge to manage as it is often difficult to keep an overview of all the devices, equipment and services. This thesis proposes an SOA based novel assimilation architecture for integrating disparate industrial hardware based processes and business processes of an enterprise in particular the plastics machinery environment. The key benefits of the proposed architecture are the reduction of complexity when integrating disparate hardware platforms; managing the associated services as well as allowing the Micro Injection Moulding (µIM) process to be monitored on the web through service and data integration. An Enterprise Service Bus (ESB) based middleware layer integrates the Wireless Sensor Network (WSN) based environmental and simulated machine process systems with frontend Google Gadgets (GGs) based web visualisation applications. A business process framework is proposed to manage and orchestrate the resulting services from the architecture. Results from the analysis of the WSN kits in terms of their usability and reliability showed that the Jennic WSN was easy to setup and had a reliable communication link in the polymer industrial environment with the PER being below 0.5%. The prototype Jennic WSN based µIM process monitoring system had limitations when monitoring high-resolution machine data, therefore a novel hybrid integration architecture was proposed. The assimilation architecture was implemented on a distributed server based test bed. Results from test scenarios showed that the architecture was highly scalable and could potentially allow a large number of disparate sensor based hardware systems and services to be hosted, managed, visualised and linked to form a cohesive business process.

Although wireless sensor networks have been successfully used for environmental monitoring, one of the major challenges that this technology has been facing is supplying continuous and reliable electrical power during long-term field deployment. Batteries require repetitive visits to the deployment site to replace them once discharged; admittedly, they can be recharged from solar panels, but this only works in open areas where solar radiation is unrestricted. This dissertation introduces a novel approach to design and implement a reliable efficient solar energy harvester to continuously, and autonomously, provide power to wireless sensor nodes for long-term applications. The system uses supercapacitors charged by a solar panel and is designed to reduce power consumption to very low levels. Field tests were conducted for more than a year of continuous operation and under a variety of conditions, including areas under dense foliage. The resulting long-term field data demonstrates the feasibility and sustainability of the harvester system for challenging applications. In addition, we analyzed solar radiation data and supercapacitor charging behavior and showed that the harvester system can operate battery free, running on the power provided by supercapacitors. A battery is included only for backup in case the supercapacitor storage fails. The proposed approach provides continuous power supply to the system thereby significantly minimizing data loss by power failure and the frequency of visits to the deployment sites.