ZyXEL Communications VFG6005, User Manual

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EAP-MD5 (Message-Digest Algorithm 5)
MD5 authentication is the simplest one-way authentication method. The authentication server sends a challenge to the
wireless stat
ion. The wireless station ‗proves‘ that it knows the password by encrypting the password with the challenge
and sends back the information. Password is not sent in plain text.
However, MD5 authentication has some weaknesses. Since the authentication server needs to get the plaintext
passwords, the passwords must be stored. Thus someone other than the authentication server may access the password
file. In addition, it is possible to impersonate an authentication server as MD5 authentication method does not perform
mutual authentication. Finally, MD5 authentication method does not support data encryption with dynamic session key.
You must configure WEP encryption keys for data encryption.
EAP-TLS (Transport Layer Security)
With EAP-TLS, digital certifications are needed by both the server and the wireless stations for mutual authentication. The
server presents a certificate to the client. After validating the identity of the server, the client sends a different certificate to
the server. The exchange of certificates is done in the open before a secured tunnel is created. This makes user identity
vulnerable to passive attacks. A digital certificate is an electronic ID card that authenticates the sender‘s identity. However,
to implement EAP-TLS, you need a Certificate Authority (CA) to handle certificates, which imposes a management
overhead.
EAP-TTLS (Tunneled Transport Layer Service)
EAP-TTLS is an extension of the EAP-TLS authentication that uses certificates for only the server-side authentications to
establish a secure connection. Client authentication is then done by sending username and password through the secure
connection, thus client identity is protected. For client authentication, EAP-TTLS supports EAP methods and legacy
authentication methods such as PAP, CHAP, MS-CHAP and MS-CHAP v2.
PEAP (Protected EAP)
Like EAP-TTLS, server-side certificate authentication is used to establish a secure connection, then use simple username
and password methods through the secured connection to authenticate the clients, thus hiding client identity. However,
PEAP only supports EAP methods, such as EAP-MD5, EAP-MSCHAPv2 and EAP-GTC (EAP-Generic Token Card), for
client authentication. EAP-GTC is implemented only by Cisco.
LEAP
LEAP (Lightweight Extensible Authentication Protocol) is a Cisco implementation of IEEE 802.1x.
Dynamic WEP Key Exchange
The AP maps a unique key that is generated with the RADIUS server. This key expires when the wireless connection times
out, disconnects or reauthentication times out. A new WEP key is generated each time reauthentication is performed.