ZyXEL Communications P-335WT - Manual (Page 486)

P-335 Series User’s Guide
486 Appendix I Wireless LANs
Shared key authentication involves a four-message procedure. A wireless station sends a
shared key authentication request to the AP, which will then reply with a challenge text
message. The wireless station must then use the AP’s default WEP key to encrypt the
challenge text and return it to the AP, which attempts to decrypt the message using the AP’s
default WEP key. If the decrypted message matches the challenge text, the wireless station is
authenticated.
When your device authentication method is set to open system, it will only accept open system
authentication requests. The same is true for shared key authentication. However, when it is
set to auto authentication, the device will accept either type of authentication request and the
device will fall back to use open authentication if the shared key does not match.
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.
If this feature is enabled, it is not necessary to configure a default encryption key in the
Wireless screen. You may still configure and store keys here, but they will not be used while
Dynamic WEP is enabled.
Note: EAP-MD5 cannot be used with Dynamic WEP Key Exchange
For added security, certificate-based authentications (EAP-TLS, EAP-TTLS and PEAP) use
dynamic keys for data encryption. They are often deployed in corporate environments, but for
public deployment, a simple user name and password pair is more practical. The following
table is a comparison of the features of authentication types.
Table 164 Comparison of EAP Authentication Types
EAP-MD5 EAP-TLS EAP-TTLS PEAP LEAP
Mutual Authentication No Yes Yes Yes Yes
Certificate – Client No Yes Optional Optional No
Certificate – Server No Yes Yes Yes No
Dynamic Key Exchange No Yes Yes Yes Yes
Credential Integrity None Strong Strong Strong Moderate
Deployment Difficulty Easy Hard Moderate Moderate Moderate
Client Identity Protection No No Yes Yes No