Christian Gottron

A Generic Metamodel for IT Security Attack Modeling for Distributed Systems

Understanding and discussing the security aspects of IT systems during their development is challenging for both domain specialists and IT experts - neglecting this aspect leads to communication problems and, eventually, to less secure systems. An important factor for these challenges is the distribution and variety of basic IT security concepts, attacks, and countermeasures, e.g., in the standard literature. In this paper, we propose a generic metamodel for IT security capturing both its major concepts and their relationships to each other. With a focus on attacks, we show how this model is applied to different scenarios in distributed systems, i.e., Peer-to-Peer systems, Service-oriented Architectures, and Mobile ad hoc Networks. This allows for a better understanding of IT security in general and attacks in particular, thus, enabling effective communication between different parties during the development of security-critical IT systems.

The rise and fall of the AODV protocol: A testbed study on practical routing attacks

Securing the routing service of Mobile Ad-hoc Networks (MANET) is a basic requirement for application scenarios such as emergency response operations. In this paper we analyze the effects of routing attacks on the Ad-hoc On-demand Distance Vector (AODV) protocol. We present results of a testbed-based analysis to consider real-world characteristics of hardware as well as wireless communications. As AODV is shown to produce unstable multi-hop routes, we design and implement a mechanism to address this issue. We then present an evaluation of three selected types of malicious behavior. Our results show that our protocol-variant delivers a reliable ad-hoc routing service. Yet, it is strongly affected by routing attacks.

A Survey on Security in Mobile Peer-to-Peer Architectures— Overlay-Based vs. Underlay-Based Approaches

Mobile Ad hoc networks (MANET) and Peer-to-Peer (P2P) networks share central characteristics such as their distributed and decentralized nature. Combining both networking paradigms results in a Mobile Peer-to-Peer (MP2P) system that operates independently from a preexisting infrastructure. Securing MP2P networks in terms of availability and robustness as basic demands in envisioned application scenarios like first responder operations is a challenging task. In this article, we present a survey of selected threats and of state of the art countermeasures for MANETs and P2P networks. Further, we discuss the efficiency of MANET and P2P security mechanisms when applied in MP2P networks.

Quality of experience of voice communication in large-scale mobile ad hoc networks

Real-time voice communication is an essential requirement in first responder scenarios. While mobile ad hoc networks (MANET) already prove to be an appropriate communication substrate in small-scale real-world operations, questions regarding scalability limitations remain. In this paper, we identify major factors that affect the quality of experience of voice communication in MANETs. In a series of simulation studies, we show that voice transmission using MANETs is also feasible in large-scale scenarios, if appropriate settings are chosen.

SMARTENERGY.KOM: An intelligent system for energy saving in smart home

Over the last twenty years, energy conservation has always been of great importance to individuals, societies and decision makers around the globe. As a result, IT researchers have shown a great interest in providing efficient, reliable and easy-to-use IT services which help users saving energy at home by making use of the current advances in Information and Communications Technology (ICT). Driven by the aforementioned motivation, we developed SMARTENERGY.KOM, our framework for realizing energy efficient smart homes based on wireless sensor networks and human activity detection. Our work is based on the idea that most of the user activities at home are related to a set of electrical appliances which are necessary to perform these activities. Therefore, we show how it is possible to detect the users current activity by monitoring his fine-grained appliance-level energy consumption. This relation between activities and electrical appliances makes it possible to detect appliances which could be wasting energy at home. Our framework is organized in two components. On one hand, the activity detection framework which is responsible for detecting the users current activity based on his energy consumption. On the other hand, the EnergyAdvisor framework which utilizes the activity detection for the purpose of recognizing the appliances which are wasting energy at home and informing the user about optimization potential.

A cluster-based locality-aware mobile peer-to-peer architecture

Mobile peer-to-peer networks combining a mobile ad hoc network underlay with a peer-to-peer overlay offer a flexible means for providing communication services in absence of a communication infrastructure. However, mobile peer-to-peer networks inherit several challenges from the underlying architectures as, e.g., strongly limited resources and a highly dynamic topology. Due to this, the overlay has to be adapted in order to provide reliable services. We introduce a mobile peer-to-peer architecture that harnesses the location awareness and clusters nodes by their location. By means of simulation, we show that the overhead generated by lookup requests, bootstrapping, and the updating mechanism of the routing tables can be strongly reduced.

Presence detection, identification and tracking in smart homes utilizing bluetooth enabled smartphones

Advances in ubiquitous computing over the last decade have allowed us to inch closer to the realization of true smart homes. Many sensors are already embedded in our living environments which can monitor several environmental parameters such as temperature, humidity, brightness and appliance-level power consumption. However, in order to achieve the primary goal of the smart home, we should be able to detect, identify, and localize the entities inside it. Therefore, the user detection, identification and localization problems represent a crucial facet of the challenges introduced by the smart home problem. Our approach towards solving these challenges entailed the usage of Bluetooth technology for user identification and tracking, alongside a Wireless Local Area Network setup to collate the sensor data at a centralized server such as a home gateway which subsequently processed and stored the entries. Moreover, we have studied the efficacy of various pattern recognition algorithms for real time processing and decision modeling on the received data. We have hence demonstrated our solution represents a non-intrusive, inexpensive and energy-conserving methodology to solve an essential part of the smart home problem by integrating already existent devices and infrastructure in an innocuous manner to obtain good results with minimum overhead.

Empirical investigation of the effect of the door's state on received signal strength in indoor environments at 2.4 GHz

Due to the wide deployment of indoor wireless local area networks (WLANs), the indoor planning became a research of interest for IT as well as networking researchers. As a result of this wide deployment, many IT applications and services started relying on the ready implemented WLAN infrastructure. Therefore, there is a need for reliable propagation models which are able to predict the WLAN signal strength in indoor environments before starting the real world deployment which leads to an efficient and cost aware deployment process. In this paper we develop an empirical propagation model which focuses mainly on the effect of the door state on the propagated WLAN signal in indoor environments. The measurements were compared to other simulated results in literature. A new empirical parameter based on empirical measurements was introduced for a better estimation of the received signal strength (RSS).

Hybrid communication architecture for emergency response — An implementation in firefighter's use case

Emergency response is a critical mission. In an emergency situation, coordination and information dissemination are two of the most important tasks. The rise of the smart mobile devices leads to the tendency to use these devices to facilitate the aforementioned tasks. Despite of that, communication based on mobile devices in an emergency situation is not always straight forward since parts of the networks might not be available at the same time. Nevertheless, it is of utmost importance to keep the information synchronized across multiple stakeholders. In this work, we design and implement a hybrid communication system to support the relief work of the responders, in particular, coordination and information synchronization among the stakeholders through the usage of mobile devices. Our focus lies on the relief works carried out by the firefighters. Our designed system is evaluated regarding its performance and its usability through a field test to show its applicability in practice.

A concept for vehicle internet connectivity for non-safety applications

Internet access to multimedia content in vehicles today is only possible via cellular networks which offer insufficient bandwidth. By using additional V2X technology in a hybrid manner, vehicles can benefit from additional bandwidth to receive enhanced internet connectivity. We introduce a holistic concept that pursues the vision of an optimal use of available access networks in a vehicular environment combined with a managed resource utilization in a user-centric way to result in maximum user experience and economic efficiency. The resulting internet connection introduces further opportunities for value-added services that maximize Quality of Experience and allows further personalization.