Wireless Client Puzzles in IEEE 802.11 Networks: Security by Wireless

Resource-depletion attacks against IEEE 802.11 access points (APs) are commonly executed by flooding APs with fake authentication requests. Such attacks may exhaust an AP’s memory resources and result in denied association service, thus enabling more sophisticated impersonation attacks accomplished by rogue APs. This work introduces the concept of wireless client puzzles, a protection method which assists an AP to preserve its resources by discarding fake requests, while allowing legitimate clients to successfully join the network. Rather than conditioning a puzzle’s solution on computational resources of highly heterogeneous clients, the puzzles utilize peculiarities of a wireless environment such as broadcast communication and signal propagation which provide more invariant properties. Using an implementation of the proposed scheme, we demonstrate its effectiveness within a realistic scenario. Based on the insights from the implementation a simulation is used to extend the threa...

• Type: Conference
• Year: 2008
• Where: WISEC
• Authors: Ivan Martinovic, Frank A. Zdarsky, Matthias Wilhelm, Christian Wegmann, and Jens B. Schmitt
• Keywords: Client Puzzles, Denial-of-Service (DoS), Impersonation Attacks, Wireless Security