Shyamnath Gollakota, Nabeel Ahmed, Nickolai Zeldovich, and Dina Katabi: This paper presents the first wireless pairing protocol that works in-band, with no pre-shared keys, and protects against MITM attacks. The main innovation is a new key exchange message constructed in a manner that ensures an adversary can neither hide the fact that a message was transmitted, nor alter its payload without being detected. Thus, any attempt by an adversary to interfere with the key exchange translates into the pairing devices detecting either invalid pairing messages or an unacceptable increase in the number of such messages. We analytically prove that our design is secure against MITM attacks, and show that our protocol is practical by implementing a prototype using off-the-shelf 802.11 cards. An evaluation of our protocol on two busy wireless networks (MIT's campus network and a reproduction of the SIGCOMM 2010 network using traces) shows that it can effectively implement key exchange in a real-world environment.
Recently: Tom Cross, Manager IBM X-Force Threat Intelligence and Strategy, talks through the challenges of using open wifi and his proposal for secure open wireless networking.
Also: I sat down last night and recorded a 70 minute long presentation on Secure Open Wireless Access. You can download the recording as a 37 Meg Quicktime Movie here. Don't forget to download our code.
Secure In-Band Wireless Pairing | 
