Greenpass: Flexible and Scalable Authorization for Wireless Networks

Wireless networks break the implicit assumptions that supported authorization in wired networks (that is: if one could connect, then one must be authorized). However, ensuring that only authorized users can access a campus-wide wireless network creates many challenges: we must permit authorized guests to access the same network resources that internal users do; we must accommodate the de-centralized way that authority flows in real universities; we also must work within standards, and accommodate the laptops and systems that users already have, without requiring additional software or plug-ins. This paper describes our ongoing project to address this problem, using SPKI/SDSI delegation on top of X.509 keypair within EAP-TLS. Within the “living laboratory” of Dartmouth’s wireless network, this project lets us solve real problem with wireless networking, while also experimenting with trust flows and testing the limits of current tools.