Secure handoff method for seamless service provisioning in infrastructure mode 802.11i system

The security mechanism specified in IEEE 802.11i is too slow to provide seamless service for a handoff session. In this paper, we propose a fast and secure handoff method at medium access control (MAC) layer by reducing authentication delay and avoiding 4-way handshake delay in the handoff process. When a mobile node (MN) handoffs to a new access point (AP), the new AP authenticates the MN instead of an authentication sever by using the security contexts transferred from the previous AP. The session key in the security context is reused only for the termination of the handoff session. Session key is refreshed when handoff session is terminated. Unlike preauthentication, the proposed method is independent of the handoff rate of the other MNs. With the proposed scheme, handoff delay could be reduced considerably while the same security level as 802.11i is maintained.