Nils Ole Tippenhauer

Learn More
In this work, we study the security of public WLAN-based positioning systems. Specifically, we investigate the Skyhook positioning system, available on PCs and used on a number of mobile platforms, including Apple's iPod touch and iPhone. By implementing and analyzing several kinds of attacks, we demonstrate that this system is vulnerable to location(More)
An increasing number of wireless applications rely on GPS signals for localization, navigation, and time synchronization. However, civilian GPS signals are known to be susceptible to spoofing attacks which make GPS receivers in range believe that they reside at locations different than their real physical locations. In this paper, we investigate the(More)
We explore the suitability of Dolev-Yao-based attacker models for the security analysis of wireless communication. The Dolev-Yao model is commonly used for wireline and wireless networks. It is defined on abstract messages exchanged between entities and includes arbitrary, real-time modification of messages by the attacker. In this work, we aim at(More)
We introduce <i>Integrity (I) regions</i>, a novel security primitive that enables message authentication in wireless networks without the use of pre-established or pre-certified keys. Integrity regions are based on the verification of entity proximity through time-of-arrival ranging techniques. We demonstrate how I-regions can be efficiently implemented(More)
In this paper we advocate the use of workflow---describing how a system provides its intended functionality---as a pillar of cybersecurity analysis and propose a holistic workflow-oriented assessment framework. While workflow models are currently used in the area of performance and reliability assessment, these approaches are designed neither to assess a(More)
—Wireless communication provides unique security challenges, but also enables novel ways to defend against attacks. In the past few years, a number of works discussed the use of friendly jamming to protect the confidentiality of the communicated data as well as to enable message authentication and access control. In this work, we analytically and(More)