wireless ad hoc networking

Wireless LAN Security 407
TLS AKA/SIM Token card
Authentication
methods
Extensible authentication protocol (EAP)
EAP layer
EAP over LANs (EAPOL)
PPP 802.3 802.5 802.11
Link layers
Figure 15.13
EAP architecture.
its peers before allowing network layer protocols to transmit data over the
link. The EAP, shown in Figure 15.13, is based on the PPP EAP. 10
Rather than specifying a fixed authentication mechanism, EAP provides
an extensible authentication platform, allowing various types of authentication
mechanisms, including EAP-MD-5, EAP-TLS (transport layer security),
EAP-PEAP (protected extensible authentication protocol), EAP-TTLS (tunneled
TLS), EAP-FAST (flexible authentication via secure tunneling), and
Cisco LEAP (lightweight extensible authentication protocol), etc. We will
discuss each of these in the following sections.
15.2.2.1 EAP-MD-5
EAP-MD-5 assumes that the supplicant and the authentication server share
a common key. It uses the MD5 algorithm to protect the password of the
supplicant. Since it only provides one-way authentication, EAP-MD-5 is
typically not recommended for wireless LAN implementations.
15.2.2.2 EAP-TLS
EAP-TLS, proposed by Microsoft and Cisco, assumes that the supplicant
and the authentication server have their own certificates for authentication.
In addition, it can dynamically generate user- and session-based WEP
keys to secure subsequent communications between the supplicant and
the authenticator. EAP-TLS provides mutual authentication between the
supplicant and the authentication server.
15.2.2.3 EAP-PEAP
EAP-PEAP, developed by Microsoft, Cisco, and RSA Security, can securely
transmit authentication data via 802.11 wireless LANs. It uses tunnels