Hans-Joachim Hof

Fighting Insomnia: A Secure Wake-Up Scheme for Wireless Sensor Networks

Sleep deprivation attacks are still an unsolved but critical problem in sensor networks. They aim on quickly exhausting energy reserves of battery-powered sensor nodes by continuously sending messages to the node, preventing the attacked node to switch to an energy-saving sleep state. Sleep deprivation attacks come also in the form of sending traffic that causes a sleeping node to wake-up. Sleep deprivation attacks have the potential to lessen the lifetime of typical sensor nodes from years to days or even hours. One important communication standard for sensor networks is IEEE 802.15.4 that defines cryptographic protection of frames. While many attacks like eavesdropping or modification of frames are covered by the available security mechanisms, these mechanisms do not address sleep deprivation attacks. This paper proposes a secure wake-up scheme that activates a sensor node by a secure wake-up radio from a sleep state only if messages from an authenticated and legitimate node are pending. A lightweight security verification scheme is used that can easily be performed without requiring the node to change to active state.

Industrial Sensor Network Security Architecture

Wireless sensor-actuator networks have a big usage potential in numerous industrial use cases. They allow easy and flexible deployment of nodes for monitoring and controlling various industrial applications as for example the supervision of critical infrastructures or monitoring and control in factory and process automation. However, missing or weak security of wireless communications would restrain the acceptance of wireless sensor-actuator networks in industrial settings. Security measures are crucial to ensure a reliable operation that is robust to accidental and targeted attacks. This paper describes the security architecture specially crafted for industrial usage environments. It provides mandatory hop-by-hop frame protection as well as authentication, access control, and protection of end-to-end communication. A secure wake-up scheme prevents a certain class of Denial-of-Service attacks, and a secure cooperative MIMO scheme improves communication reliability.

Security Design for Industrial Sensor Networks

Abstract The industrial application of wireless sensor-actuator networks is attractive due to their flexibility, saving potential and ease of use. However, weak or missing security would restrain the acceptance and hinder a wide-spread use. This paper presents a security design for wireless sensor-actuator networks in industrial settings. The security design provides mandatory frame protection as well as end-to-end communication protection, authentication, and access control. Additional security mechanisms for MIMO transmission and node wake-up are described. Zusammenfassung Sensor-Aktor-Netze sind durch ihre Flexibilität, Einfachheit und potentielle Kostenersparnis für industrielle Anwendungen von großem Interesse, fehlende Sicherheit kann jedoch die Akzeptanz verhindern. Im Folgenden wird ein Sicherheitsentwurf für industrielle Anwendungen von drahtlosen Sensor-Aktor-Netzen präsentiert, welches unter anderem den obligatorischen Schutz von Daten-Frames, Ende-zu-Ende-Kommunikationssicherheit, Authentifizierung und Access Control beinhaltet. Darüberhinaus werden Sicherheitsmechanismen für sichere MIMO Übertragung und sicheres Aufwecken von Sensorknoten beschrieben.