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Popovic V.,Ecole Polytechnique Federale de Lausanne | Ott B.,Armasuisse | Wellig P.,Armasuisse | Leblebici Y.,Ecole Polytechnique Federale de Lausanne
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Recent technological advancements in hardware systems have made higher quality cameras. State of the art panoramic systems use them to produce videos with a resolution of 9000 x 2400 pixels at a rate of 30 frames per second (fps).1 Many modern applications use object tracking to determine the speed and the path taken by each object moving through a scene. The detection requires detailed pixel analysis between two frames. In fields like surveillance systems or crowd analysis, this must be achieved in real time.2 In this paper, we focus on the system-level design of multi-camera sensor acquiring near-infrared (NIR) spectrum and its ability to detect mini-UAVs in a representative rural Swiss environment. The presented results show the UAV detection from the trial that we conducted during a field trial in August 2015. © 2016 SPIE.


Heinzer P.,ETH Zurich | Lenders V.,armasuisse | Legendre F.,ETH Zurich
Proceedings - IEEE INFOCOM | Year: 2012

Fast and accurate link quality estimation is an important feature for wireless protocols such as routing, rate switching or handover. Existing signal strength based estimators tend to be fast but inaccurate while packet statistic based approaches are more accurate but require longer estimation times. We propose a new link quality estimation approach based on chip errors in symbols for direct sequence spread spectrum transceivers. The new link quality estimator is evaluated experimentally with software defined radios on IEEE 802.15.4 for different link conditions, including multi-path and mobile scenarios. We show that our chip error based link quality estimator performs more accurately than received signal strength based estimators and much faster than the packet statistic based estimators with comparable accuracy. With our approach, only a single packet, or even a fraction of a packet (e.g., only a few symbols), is necessary to obtain similar performance as state-of-the-art approaches that require at least 10 packets. © 2012 IEEE.


Gugelmann D.,ETH Zurich | Schatzmann D.,ETH Zurich | Lenders V.,Armasuisse
ASIA CCS 2013 - Proceedings of the 8th ACM SIGSAC Symposium on Information, Computer and Communications Security | Year: 2013

This paper presents Horizon Extender, a system for long-term preservation of data leakage evidence in enterprise networks. In contrast to classical network intrusion detection systems that keep only packet records of suspicious traffic (black-listing), Horizon Extender reduces the total size of captured network traces by filtering out all records that do not reveal potential evidence about leaked data (white-listing). Horizon Extender has been designed to exploit the inherent redundancy and adherence to protocol specification of general Web traffic. We show in a real-life network including more than 1000 active hosts that Horizon Extender is able to reduce the total HTTP volume by 99.8%, or the outgoing volume by 90.9% to 93.9%, while preserving sufficient evidence to recover retrospectively time, end point identity, and content of information leaked over the HTTP communication channel. © 2013 ACM.


Huber S.,Forventis GmbH | Wellig P.,Armasuisse
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

Background: Algorithms show difficulties in distinguishing weak signals of a target from a cluttered background, a task that humans tend to master relatively easily. We conducted two studies to identify how various degrees of clutter influence operator performance and search patterns in a visual target detection task. Methods: First, 8 male subjects had to look for specific female targets within a heavily cluttered public area. Subjects were supported by differing amounts of markings that helped them to identify females in general. We presented video clips and analyzed the search patterns. Second, 18 subject matter experts had to identify targets on a heavily frequented motorway intersection. We presented them with video material from a UAV (Unmanned Aerial Vehicle) surveillance mission. The video image was subdivided in three zones: The central zone (CZ), a circle area of 10°. The peripheral zone (PZ) corresponding to a 4:3 format and the hyper peripheral zone (HPZ) which represented the lateral region specific to the 16:9 format. We analyzed fixation densities and task performance. Results: We found an approximately U-shaped correlation between the number of markings in a video and the degree of structure in search patterns as well as performance. For the motorway surveillance task we found a difference in mean detection time for CZ vs. HPZ (p=0.01) and PZ vs. HPZ (p=0.003) but no difference for CZ vs. PZ (p=0.491). There were no differences in detection rate for the respective zones. We found the highest fixation density in CZ decreasing towards HPZ. Conclusion: We were able to demonstrate that markings could increase surveillance operator performance in a cluttered environment as long as their number is kept in an optimal range. When performing a search task within a heavily cluttered environment, humans tend to show rather erratic search patterns and spend more time watching central picture areas. © 2015 SPIE.


Koch A.,Armasuisse | Bianchi S.,RUAG Land Systems AG
25th International Symposium on Ballistics, ISB 2010 | Year: 2010

Steel is the most used material for the confinement plates of explosive reactive armours, but other materials afford better protection against shaped charges. One of the most interesting material is ceramic because of its hardness, of its relatively small density and of the reduction of collateral damages. We have therefore compared the protection efficiency of reactive armours built either with steel or with alumina plates. We varied both the weight of the confinement plates and the thickness of the explosive sheet. For each configuration, we measured the protection efficiency against a standard shaped charge. Clear correlations arc observed between the weight of the confinement plates or the amount of contained explosive, on the one hand, and the protection efficiency of the reactive armour, on the other hand.


Schafer M.,University of Kaiserslautern | Lenders V.,Armasuisse | Martinovic I.,University of Oxford
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

This work studies the security of next generation air traffic surveillance technology based on Automatic Dependent Surveillance - Broadcast (ADS-B). ADS-B is already supported by a majority of international aircraft and will become mandatory in 2020 for most airspaces worldwide. While it is known that ADS-B might be susceptible to different spoofing attacks, the complexity and impact of launching these attacks has been debated controversially by the air traffic control community. Yet, the literature remains unclear on the requirements of launching ADS-B attacks in real-world environments, and on the constraints which affect their feasibility. In this paper, we take a scientific approach to systematically evaluate realistic ADS-B attacks. Our objective is to shed light on the practicability of different threats and to quantify the main factors that impact the success of such attacks. Our results reveal some bad news: attacks on ADS-B can be inexpensive and highly successful. Using a controlled experimental design, we offer insights from a real-world feasibility analysis that leads to the conclusion that any safety-critical air traffic decision process should not rely exclusively on the ADS-B system. © 2013 Springer-Verlag.


Wilhelm M.,University of Kaiserslautern | Martinovic I.,University of California at Berkeley | Schmitt J.B.,University of Kaiserslautern | Lenders V.,Armasuisse
Proceedings of the ACM SIGCOMM 2011 Conference, SIGCOMM'11 | Year: 2011

Firewalls are extremely effective at enforcing security policies in wired networks. Perhaps surprisingly, firewalls are entirely nonexistent in the wireless domain. Yet, the need to selectively control and block radio communication is particularly high in a broadcast environment since any node may receive and send packets. In this demo, we present WiFire, a system that brings the firewall concept to wireless networks. First, WiFire detects and analyzes packets during their transmission, checking their content against a set of rules. It then relies on reactive jamming techniques to selectively block undesired communication. We show the feasibility and performance of WiFire, which is implemented on the USRP2 software-defined radio platform, in several scenarios with IEEE 802.15.4 radios. WiFire is able to classify and effectively block undesired communication without interfering with desired communication.


Lenders V.,Armasuisse
2013 Workshop on Sensor Data Fusion: Trends, Solutions, Applications, SDF 2013 | Year: 2013

Conventional Web search models are ineffective at providing quick and comprehensive answers to questions related to live content such as real-time data or temporal relationships between actors. Semantic data fusion techniques have the potential to provide a more suitable abstraction model for efficient search on this type of data. However, myriad architectural and technical implementation challenges arise when trying to implement a working system. This paper summarizes our efforts and experiences at implementing a functional semantic fusion system for live content from the Web. Besides semantic data fusion techniques, we make extensive use of natural language processing, semantic Web technologies and Bayesian statistics to render the system a self-contained framework acting directly between Web resources of interest and end-user search applications. We first present the semantic fusion architecture design that we have developed. We have implemented this architecture and tested its effectiveness using real-world live data from the Web over multiple weeks. We then report about our major experiences and lessons-learned of this experiment. © 2013 IEEE.


Wilhelm M.,University of Kaiserslautern | Martinovic I.,University of Kaiserslautern | Schmitt J.B.,University of Kaiserslautern | Lenders V.,Armasuisse
WiSec'11 - Proceedings of the 4th ACM Conference on Wireless Network Security | Year: 2011

In this work, we take on the role of a wireless adversary and investigate one of its most powerful tools - radio frequency jamming. Although different jammer designs are discussed in the literature, reactive jamming, i.e., targeting only packets that are already on the air, is generally recognized as a stepping stone in implementing optimal jamming strategies. The reason is that, while destroying only selected packets, the adversary minimizes its risk of being detected. One might hope for reactive jamming to be too challenging or uneconomical for an attacker to conceive and implement due to its strict real-time requirements. Yet, in this work we disillusion from such hopes as we demonstrate that flexible and reliable software-defined reactive jamming is feasible by designing and implementing a reactive jammer against IEEE 802.15.4 networks. First, we identify the causes of loss at the physical layer of 802.15.4 and show how to achieve the best performance for reactive jamming. Then, we apply these insights to our USRP2-based reactive jamming prototype, enabling a classification of transmissions in real-time, and reliable and selective jamming. The prototype achieves a reaction time in the order of microseconds, a high precision (such as targeting individual symbols), and a 97.6 % jamming rate in realistic indoor scenarios for a single reactive jammer, and over 99.9 % for two concurrent jammers. Copyright © 2011 ACM.


Schafer M.,University of Kaiserslautern | Lenders V.,Armasuisse | Schmitt J.,University of Kaiserslautern
Proceedings - IEEE Symposium on Security and Privacy | Year: 2015

We propose a new approach for securely verifying sequences of location claims from mobile nodes. The key idea is to exploit the inherent mobility of the nodes in order to constrain the degree of freedom of an attacker when spoofing consecutive location updates along a claimed track. We show that in the absence of noise, our approach is able to securely verify any 2-D track with a minimum of three verifiers or any 3-D track with four verifiers. Our approach is lightweight in the sense that it considerably relaxes the system requirements compared to previous secure location verification schemes which are all agnostic to mobility. As opposed to previous schemes, our track verification solution is at the same time (i) passive, (ii) does not require any time synchronization among the verifiers, (iii) does not need to keep the location of the verifiers secret, (iv) nor does it require specialized hardware. This makes our solution particularly suitable for large-scale deployments. We have evaluated our solution in a realistic air traffic monitoring scenario using real-world data. Our results show that 25 position claims on a track are sufficient to detect spoofing attacks with a false positive rate of 1.4% and a false negative rate of 1.2%. For tracks with more than 40 claims, the false positive and false negative rates drop to zero. © 2015 IEEE.

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