The Location Service (LCS) proposed by the telecommunication industry is an architecture that allows the location of mobile devices to be accessed in various applications. We explore the use of LCS in location-enhanced server authentication, which traditionally relies on certificates. Given recent incidents involving certificate authorities, various techniques to strengthen server authentication were proposed. They focus on improving the certificate validation process, such as pinning, revocation, or multi-path probing. In this paper, we propose using the server's geographic location as a second factor of its authenticity. Our solution, SALVE, achieves location-based server authentication by using secure DNS resolution and by leveraging LCS for location measurements. We develop a TLS extension that enables the client to verify the server's location in addition to its certificate. Successful server authentication therefore requires a valid certificate and the server's presence at a legitimate geographic location, e.g., on the premises of a data center. SALVE prevents server impersonation by remote adversaries with mis-issued certificates or stolen private keys of the legitimate server. We develop a prototype implementation and our evaluation in real-world settings shows that it incurs minimal impact to the average server throughput. Our solution is backward compatible and can be integrated with existing approaches for improving server authentication in TLS.

While frequent reports on targeted attacks for Industrial Control Systems hit the news, the amount of untargeted attacks using standardized industrial protocols is still unclear, especially if devices are mistakenly or even knowingly connected to the Internet. To lay the foundation for a deeper insight into the interest of potential attackers, a large scale honeynet system that captures all interactions using industrial protocols is proposed. Special for the honeynet system architecture is the automated deployment on a cloud infrastructure and its modularisation of the industrial protocols. The centralized-but-redundant data collection allows correlating attacks that happen on multiple devices. A real-world experiment confirms the feasibility of the approach, and results of the observed interactions with the honeynet are presented.

Power companies are deploying a multitude of sensors to monitor the energy grid. Measurements at different locations should be aligned in time to obtain the global state of the grid, and the industry therefore uses GPS as a common clock source. However, these sensors are exposed to GPS time spoofing attacks that cause misaligned aggregated measurements, leading to inaccurate monitoring that affects power stability and line fault contingencies. In this paper, we analyze the resilience of phasor measurement sensors, which record voltages and currents, to GPS spoofing performed by an adversary external to the system. We propose a solution that leverages the characteristics of multiple sensors in the power grid to limit the feasibility of such attacks. In order to increase the robustness of wide-area power grid monitoring, we evaluate mechanisms that allow collaboration among GPS receivers to detect spoofing attacks. We apply multilateration techniques to allow a set of GPS receivers to locate a false GPS signal source. Using simulations, we show that receivers sharing a local clock can locate nearby spoofing adversaries with sufficient confidence.