Cryptographic key management methods for mission-critical wireless networks

When a large scale disaster strikes, it demands an efficient communication and coordination among first responders to save life and other community resources. Normally, the traditional communication infrastructures such as landline phone or cellular networks are damaged and dont provide adequate communication services to first responders for exchanging emergency related information. Wireless mesh networks is the promising alternatives in such type of situations. The security requirements for emergency response communications include privacy, data integrity, authentication, access control and availability. To build a secure communication system, usually the first attempt is to employ cryptographic keys. In critical-mission wireless mesh networks, a mesh router needs to maintain secure data communication with its neighboring mesh routers. The effective designs on fast pairwise key generation and rekeying for mesh routers are critical for emergency response and are essential to protect unicast traffic. In this paper, we present a security-enhanced session key generation and rekeying protocols EHPFS (enhanced 4-way handshake with PFS support). It eliminate the DoS attack problem of the 4-way handshake in 802.11s. EHPFS provides additional support for perfect forward secrecy (PFS). Even in case a Primary Master Key (PMK) is exposed, the session key PTK will not be compromised. The performance and security analysis show that EHPFS is efficient.