Analysing the EAP-TLS Handshake and the 4-Way Handshake of the 802.11i Standard
Abdullah Alabdulatif, Xiaoqi Ma · International Journal for Information Security Research · 2014
The IEEE 802.11i standard has been designed to enhance security in wireless networks.The EAP-TLS handshake aims to provide mutual authentication between supplicant and authentication server, and then derive the Pairwise Master Key (PMK).In the 4-way handshake the supplicant and the authenticator use PMK to derive a fresh pairwise transient key (PTK).The PMK is not used directly for security while assuming the supplicant and authenticator have the same PMK before running 4way handshake.In this paper, the EAP-TLS handshake and the 4-way handshake phases have been analysed with a proposed framework using Isabelle tool.In the analysis, we have found a new Denial-of-Service (DoS) attack in the 4-way handshake.The attack prevents the authenticator from receiving message 4 after the supplicant sends it out.This attack forces the authenticator to re-send the message 3 until time out and subsequently to deauthenticate supplicant.This paper has proposed improvements to the 4-way handshake to avoid the Denial-of-Service attack.