Intrusion-Resilient Integrity in Data-Centric Unattended WSNs

Unattended Wireless Sensor Networks (UWSNs) operate in autonomous or disconnected mode: sensed data is collected periodically by an itinerant sink. Between successive sink visits, sensor-collected data is subject to some unique vulnerabilities. In particular, while the network is unattended, a mobile adversary (capable of subverting up to a fraction of sensors at a time) can migrate between compromised sets of sensors and inject fraudulent data. In this paper, we provide two collaborative authentication techniques that allow an UWSN to maintain integrity and authenticity of sensor data-in the presence of a mobile adversary-until the next sink visit. Proposed schemes use simple, standard, and inexpensive symmetric cryptographic primitives, coupled with key evolution and few message exchanges. We study their security and effectiveness, both analytically and via simulations. We also assess their robustness and show how to achieve the desired trade-off between performance and security

A Survey on Wireless Sensor Network Security

Wireless sensor networks (WSNs) have recently attracted a lot of interest in the research community due their wide range of applications. Due to distributed nature of these networks and their deployment in remote areas, these networks are vulnerable to numerous security threats that can adversely affect their proper functioning. This problem is more critical if the network is deployed for some mission-critical applications such as in a tactical battlefield. Random failure of nodes is also very likely in real-life deployment scenarios. Due to resource constraints in the sensor nodes, traditional security mechanisms with large overhead of computation and communication are infeasible in WSNs. Security in sensor networks is, therefore, a particularly challenging task. This paper discusses the current state of the art in security mechanisms for WSNs. Various types of attacks are discussed and their countermeasures presented. A brief discussion on the future direction of research in WSN security is also included.Comment: 24 pages, 4 figures, 2 table

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

Indoor wireless metering networks - A collection of algorithms enabling low power / low duty-cycle operations

Die Bezeichnung Wireless Metering Network (WMN) identifiziert eine spezifische Klasse von drahtlosen Sensornetzwerken. Solche Netze bestehen aus einer Vielzahl von kleinen, kostengünstigen batteriebetriebenen Knoten und bieten eine mögliche Lösung für unterschiedliche Aufgaben in der Gebäudeautomatisierung, vorausgesetzt dass die erwartete Lebensdauer des Netzes mindestens 10 Jahre betragt, um die Netzwerkwartung im selben Raster mit den Gebäudewartungsarbeiten planen zu können. Die starken Energieeinschränkungen erfordern die Einführung von Energiesparmaßnahmen und insbesondere die Auswahl einer durch einen extrem geringen Arbeitszyklus charakterisierten Aktivierungsstrategie. Schlüsselelemente für den Erfolg eines WMN-Projektes sind die Existenz eines energieeffizienten MAC-Protokolls, der Einsatz eines robusten Zeitsynchronisationsmechanismus und die Implementierung von effizienten Strategien für die Netzwerkinitialisierung und die Netzwerkwartung. Hauptziel dieser Arbeit war die Entwicklung von Algorithmen und Protokollen, mit denen der energieeffiziente Betrieb einer spezifischen Familie von WSN ermöglicht wird. Die Entwicklung und die Validierung eines Ausbreitungsmodells für den Indoor-Funkkanal war ein erforderlicher Schritt, um die Untersuchung der entwickelten Verfahren zu ermöglichen. Das erste im Rahmen des Projektes entstandene Ergebnis war ein heuristischer, robuster verteilter Algorithmus, der eine energieeffiziente Integration aller Sensorknoten und die Bildung einer robusten baumförmigen Routingstruktur ermöglicht. Derselbe Algorithmus ermöglicht eine begrenzte Anpassung der Netzstruktur an die wechselnden Charakteristiken des Funkkanals. Einfache Erweiterungen des ursprünglichen Algorithmus wurden hinzugefügt, um die Selbstheilungsfähigkeiten des Netzes zu verbessern. Ein auf einer neuen Formulierung des Synchronisationsproblems basierendes Verfahren wurde entwickelt. Es gewährleistet eine energieeffiziente und robuste Zeitsynchronisation zwischen Nachbarnknoten und, indirekt, die Synchronisation aller Netzelemente. Obwohl die vorgeschlagenen Lösungen für eine spezifische Netzkategorie entwickelt wurden, ist der Autor überzeugt, dass sich die Lösungsansätze auf ein weites Spektrum von Problemen anwenden lassen.Wireless Metering Networks (WMN), a special class of Wireless Sensor Networks (WSN), consisting of a large number of tiny inexpensive sensor nodes are a viable solution for many problems in the field of building automation especially if the expected lifetime of the network permits to synchronize the network maintenance with the schedule for routine maintenance of the building. In order to meet the resulting energy constraints, the nodes have to operate according to an extremely low duty cycle schedule. The existence of an energy efficient MAC Layer protocol, the adoption of a robust time synchronization mechanism and the implementation of effective network discovery and maintenance strategies are key elements for the success of a WMN project. The main goal of this work was the development of a set of algorithms and protocols which enable the low energy / low power operation in the considered family of WMNs. The development and validation of a propagation model reproducing the characteristics of the indoor radio environment was a necessary step in order to obtain appropriate instruments for the evaluation of the quality of the proposed solutions. The author suggests a simple localized heuristic algorithm which permits the integration of all sensor nodes into a tree-like failure tolerant routing structure and also provides some basic continuous adaptation capabilities of the network structure.\\ A subsequent extension of the basic algorithm makes the network able of self healing. An innovative approach to the solution of the synchronization problem based on a reformulation of the original problem into an estimation problem permitted the development of an efficient time synchronization mechanism. This mechanism, which makes an opportunistic usage of the beacon signals generated by the MAC layer protocol, permits an effective reduction of the synchronization error between directly communicating nodes and, indirectly, introduces a global synchronization among all nodes. All the proposed solutions have been developed for a specific network class. However, since the presence of a low duty cycle scheduling, the adoption of a beacon enabled MAC protocol and the presence of limited hardware resources are quite general assumptions, the author feels confident about the applicability of the proposed solution to a much wider spectrum of problems

Ten years of cooperation between mobile robots and sensor networks

This paper presents an overview of the work carried out by the Group of Robotics, Vision and Control (GRVC) at the University of Seville on the cooperation between mobile robots and sensor networks. The GRVC, led by Professor Anibal Ollero, has been working over the last ten years on techniques where robots and sensor networks exploit synergies and collaborate tightly, developing numerous research projects on the topic. In this paper, based on our research, we introduce what we consider some relevant challenges when combining sensor networks with mobile robots. Then, we describe our developed techniques and main results for these challenges. In particular, the paper focuses on autonomous self-deployment of sensor networks; cooperative localization and tracking; self-localization and mapping; and large-scale scenarios. Extensive experimental results and lessons learnt are also discussed in the paper

Test and evaluation of a prototyped sensor-camera network for persistent intelligence, surveillance, and reconnaissance in support of tactical coalition networking environments

This thesis investigated the feasibility of deploying an integrated sensor-camera network in military and law enforcement applications. The system was built using entirely commercial-off-the-shelf technologies. The prototype used the unattended ground sensors combined with digital video surveillance cameras to provide accurate real-time situational awareness, persistent intelligence and remote security. A robust testing and evaluation plan was created to measure the system's performance based on specific metrics. The tests focused primarily on the capabilities of the sensor aspect of the network. Tests were conducted to determine the maximum detection range, probabilities of detection, maximum communications range, and battery life. Mathematical models were created to assist network planners. Additionally, the prototyped system was tested through field exercises as part of the Naval Postgraduate School's Coalition Operating Area Surveillance and Targeting System field demonstrations in California and northern Thailand. Although the sensing capabilities exceeded the minimum metrics, the system was not suitable for use in military applications. However, the prototyped network would work well in less demanding law enforcement environments. Additionally, the feasibility and the need to develop an integrated sensor-camera network were demonstrated.http://archive.org/details/testndevaluation109452780US Navy (USN) author.Approved for public release; distribution is unlimited

A survey on fault diagnosis in wireless sensor networks

Wireless sensor networks (WSNs) often consist of hundreds of sensor nodes that may be deployed in relatively harsh and complex environments. In views of hardware cost, sensor nodes always adopt relatively cheap chips, which makes these nodes become error-prone or faulty in the course of their operation. Natural factors and electromagnetic interference could also influence the performance of the WSNs. When sensor nodes become faulty, they may have died which means they cannot communicate with other members in the wireless network, they may be still alive but produce incorrect data, they may be unstable jumping between normal state and faulty state. To improve data quality, shorten response time, strengthen network security, and prolong network lifespan, many studies have focused on fault diagnosis. This survey paper classifies fault diagnosis methods in recent five years into three categories based on decision centers and key attributes of employed algorithms: centralized approaches, distributed approaches, and hybrid approaches. As all these studies have specific goals and limitations, this paper tries to compare them, lists their merits and limits, and propose potential research directions based on established methods and theories