Michael Niedermeier

Review: Dynamic key management in wireless sensor networks: A survey

Wireless sensor networks (WSNs) have a vast field of applications, including environment monitoring, battlefield surveillance and target tracking systems. As WSNs are usually deployed in remote or even hostile environments and sensor nodes are prone to node compromise attacks, the adoption of dynamic key management is extremely important. However, the resource-constrained nature of sensor nodes hinders the use of dynamic key management solutions designed for wired and ad hoc networks. Hence, many dynamic key management schemes have been proposed for WSNs recently. This paper investigates the special requirements of dynamic key management in sensor network environments, and introduces several basic evaluation metrics. In this work, the state of the art dynamic key management schemes are classified into different groups and summarized based on the evaluation metrics. Finally, several possible future research directions for dynamic key management are provided.

Quality Assessment of the MPEG-4 Scalable Video CODEC

In this paper, the performance of the emerging MPEG-4 SVC CODEC is evaluated. In the first part, a brief introduction on the subject of quality assessment and the development of the MPEG-4 SVC CODEC is given. After that, the used test methodologies are described in detail, followed by an explanation of the actual test scenarios. The main part of this work concentrates on the performance analysis of the MPEG-4 SVC CODEC - both objective and subjective. Please note that this document is only a shortened version of the assessment. Further experimental results can be found in the extended version available at the Computing Research Repository (CoRR).

Critical Infrastructure Surveillance Using SecureWireless Sensor Networks

In this work, a secure wireless sensor network (WSN) for the surveillance, monitoring and protection of critical infrastructures was developed. To guarantee the security of the system, the main focus was the implementation of a unique security concept, which includes both security on the communication level, as well as mechanisms that ensure the functional safety during its operation. While there are many theoretical approaches in various subdomains of WSNs—like network structures, communication protocols and security concepts—the construction, implementation and real-life application of these devices is still rare. This work deals with these aforementioned aspects, including all phases from concept-generation to operation of a secure wireless sensor network. While the key focus of this paper lies on the security and safety features of the WSN, the detection, localization and classification capabilities resulting from the interaction of the nodes’ different sensor types are also described.

Constructing Dependable Smart Grid Networks using Network Functions Virtualization

Smart meters enable a fine-granular monitoring of power consumption and distributed power production in costumers’ premises, which are used to predict the power requirements for the near future. The goals are to offer more security of supply as well as to minimize the power requirement estimation errors. However, to benefit from this information, the communication infrastructure that transmits the energy-related data needs to fulfill stringent requirements with respect to dependability, while remaining monetarily feasible. This paper discusses the usage of network function virtualization (NFV) technologies and constructs a virtual advanced metering infrastructure (AMI) network to transmit energy-related information in a dependable and cost-effective way. After the discussion of dependability requirements of AMI and the shortcomings of current approaches, the reliability and availability of a new architecture based on NFV is analyzed using analysis. Finally, a cost model is developed to compare the Virtual Network Function approach to current AMIs.

RESA: A Robust and Efficient Secure Aggregation Scheme in Smart Grids

In this paper, we indicate the increasing interests in providing network security and privacy in Smart Grids, and propose a novel usage data aggregation scheme. The proposed scheme combines multiple cryptosystems to achieve anonymity and multidimensional data aggregation without a trusted third party. In our approach, smart meters transmit usage reports through hop-by-hop communication. If the communication is delayed or fails at one hop, it is possible to reroute the traffic through another hop. Therefore, the robustness of grid communication networks is improved. Additionally, an aggregation tree is constructed in order to optimize the aggregation time. Finally, smart meters utilize a highly efficient hash-based message authentication code to ensure data integrity and identity authentication. Although some existing approaches can achieve similar security features, our scheme has lower computational cost according to performance analysis and experiments.

Sicherheitsherausforderungen in hochverteilten Systemen

Schon seit Langem spielen verteilte IT-Systeme eine entscheidende Rolle in der Datenverarbeitung. Infolge der zunehmenden Vernetzung durch das Internet wurde es in den letzten Jahren moglich, global erreichbare, hochverteilte Systeme zu erschaffen. Durch die rasante Entwicklung derartiger Systeme entstehen einerseits neue Anforderungen an die Performanz (z.B. Leistungsfahigkeit und Bandbreite), wahrend andererseits die steigende Komplexitat von hochverteilten Systemen deren Absicherung (z.B. Datensicherheit und Datenschutz) immer schwieriger gestaltet. Zwei hochaktuelle Beispiele fur hochverteilte Systeme sind Smart Grid und Cloud Computing, die im Folgenden naher betrachtet werden. Smart Grid – Energieinformationsnetzwerke der Zukunft Das intelligente Elektrizitatsnetz (“Smart Grid”) wird langfristig unser heutiges, starres und hierarchisches Stromnetz ablosen. Kernziele des Smart Grid sind die Integration erneuerbarer Energiequellen, eine erhohte Versorgungssicherheit, sowie die Bereitstellung von Infrastrukturen fur eMobilitat unter Berucksichtigung effizienter Verfahren hinsichtlich der Energieverwendung. Zur Realisierung dieser Ziele sind mehrere Schritte notwendig. Als Basis dieser Entwicklung dient die Verflechtung des bisher isolierten Energienetzes mit modernen Kommunikationsinfrastrukturen (vgl. Berl et al. 2013). Dies erlaubt die Integration dezentraler Energieproduktions- (z.B. Photovoltaik) und Energiespeicheranlagen (z.B. Akkumulatoren im Bereich eMobilitat), sowie die Verwendung von intelligenten Stromzahlern („Smart Meter“) und ermoglicht damit eine neue Qualitat des Energiemanagements (z.B. durch Fernwartung und -uberwachung). Neben den entstehenden Chancen durch diese

TAI: A Threshold-Based Anonymous Identification Scheme for Demand-Response in Smart Grids

Smart grids offer benefits compared to the current power grid by using technologies, such as advanced metering infrastructure and demand-response schemes. However, the introduction of these technologies also leads to challenges in the areas of privacy and identification of disobedient users. Current solutions to these challenges heavily rely on a trusted third party, which may lead to scenarios where the privacy of obedient consumers cannot be preserved. To tackle these concerns, anonymity provides a promising approach to obviating privacy preservation in smart grids. In this paper, a threshold-based anonymous identification scheme (TAI) for overload audit and privacy preservation in smart grids is proposed, where the use of a trusted third party is no longer required. Privacy preservation depends on the power consumption of consumers in the presence of a demand-response request from the power provider that defines an acceptable consumption threshold at periods of power shortage. Consumers must follow the instruction and curtail their consumption to meet the threshold. By doing so, the consumers who adhere to the power providers’ instructions keep their anonymity, whilst the disobedient are be identified. According to our security and performance analysis, TAI significantly improves efficiency compared to previous anonymous identification schemes, while providing anonymity and identification.

Virtual Energy Information Network: a resilience perspective

Increasing demand in energy consumption, missed modernisations, and the increasing difficulties in predicting power production due to volatile renewable energy sources (e.g., based on wind or sun) impose major challenges to the power grid. Power supply and power demand are closely interconnected with the need to maintain the power grid in a stable state with a sufficient quality of power. This requires energy-relevant information to be exchanged through the so called Energy Information Network. Communication, however, is challenging within the Energy Information Network due to privacy, security, resiliency, and quality-of-service requirements. Particularly, the resilience of communication within the Energy Information Network needs to be considered to maintain the power grid in a stable and controlled state. This paper suggests a Virtualised Energy Information Network (VEIN), where the Energy Information Network is divided into multiple virtual networks that run over a common substrate network. Furthermore, this paper discusses benefits of this approach in terms of privacy, security, and resilience and points out open research questions.ZusammenfassungSteigender Energieverbrauch, nicht durchgeführte Modernisierungen und steigende Komplexität in der Vorhersage der Produktion von erneuerbaren Energien (durch Sonne oder Wind) stellen große Herausforderungen für das Stromnetz dar. Energienachfrage und Energieversorgung sind stark verbunden mit der Notwendigkeit, das Stromnetz in einem stabilen Zustand mit hoher Stromqualität zu halten. Um das zu erreichen, müssen energiebezogene Informationen im so genannten Energieinformationsnetz ausgetauscht werden. Die Kommunikation im Energieinformationsnetz ist allerdings großen Herausforderungen unterworfen, wie etwa Anforderungen an Privatheit, Sicherheit, Widerstandsfähigkeit und Dienstgüte. Speziell die Widerstandsfähigkeit des Energieinformationsnetzes muss gewährleistet sein, um das Stromnetz in einem stabilen und kontrollierten Zustand zu halten. Dieser Beitrag schlägt ein Virtualisiertes EnergieInformationsNetz (VEIN) vor, in dem das Energieinformationsnetz in mehrere virtuelle Netze geteilt wird, die über ein gemeinsames Substratnetz laufen. Die Vorteile dieses Ansatzes werden in Bezug auf Privatheit, Sicherheit und Widerstandsfähigkeit diskutiert, und offene Forschungsfragen werden aufgezeigt.

Smart Grid Considerations: Energy Efficiency vs. Security

Abstract The Smart Grid is expected to increase the efficiency of the current power grid, to cope with volatile power production based on renewable resources, to reduce the need for fossil-based energy resources, and to guarantee the stability of power supply. To achieve these objectives, today’s power grid is enhanced by information and communication technology to increase the information flow and to enable a sophisticated power production and power demand management. However, as the power grid is extended to a network of networks, it does not only become smarter, but also more vulnerable to security threats. This chapter discusses the current status and future developments of the Smart Grid and its challenges. Enhancements in terms of energy efficiency and new energy management approaches are covered as well as novel security challenges in different parts of the Smart Grid architecture. In short, this chapter analyzes some of the most striking risks and threats concerning the new Smart Grid infrastructure and discusses interdependencies between energy efficiency and security in the Smart Grid.

MOVEDETECT – Secure Detection, Localization and Classification in Wireless Sensor Networks

In this paper a secure wireless sensor network (WSN) developed within the MOVEDETECT project is presented. The goal of the project was to design, implement and demonstrate a secure WSN for the protection of critical infrastructure. In order to provide a reliable service, the system must detect any kind of tampering with the sensor nodes, prevent eavesdropping and manipulation of the communication as well as detect, track and classify intruders in the protected region. Therefore based on previous experiences, a real-world WSN was developed, which addresses practical issues like water proofing, energy consumption, sensor deployment and visualization of the WSN state, but also provides a unique security concept, a interesting combination of sensors and sophisticated sensor data processing and analysis. The system was evaluated by examining firstly the sensors and the sensor processing algorithms and then conducting realistic field test.