A jamming approach to enhance enterprise Wi-Fi secrecy through spatial access control

Prevalent Wi-Fi networks have adopted various protections to prevent eavesdropping caused by the intrinsic shared nature of wireless medium. However, many of them are based on pre-shared secret incurring key management costs, and are still vulnerable from practical countermeasures. In this study, we investigate the feasibility of using defensive jamming technique to protect enterprise Wi-Fi networks from potential eavesdroppers. This non-cryptographic approach requires neither any pre-shared key or high deployment costs. Defensive jammers geographically confine the wireless coverage of Wi-Fi access point (AP), and thus block the message reception outside an arbitrary boundary at a physical layer. We provide a theoretical model fine tuning the jamming parameters for jammer placement. We then discuss practical considerations including optimized jammer arrangement algorithms, interference countermeasures to legitimate communications, and countermeasures against advanced attackers.