ZyXEL Communications Prestige 661H Series, User Manual

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Prestige 661H/HW Series User’s Guide
511 Appendix L Wireless LANs
The Message Integrity Check (MIC) is designed to prevent an attacker from capturing data
packets, altering them and resending them. The MIC provides a strong mathematical function
in which the receiver and the transmitter each compute and then compare the MIC. If they do
not match, it is assumed that the data has been tampered with and the packet is dropped.
By generating unique data encryption keys for every data packet and by creating an integrity
checking mechanism (MIC), TKIP makes it much more difficult to decrypt data on a Wi-Fi
network than WEP, making it difficult for an intruder to break into the network.
The encryption mechanisms used for WPA and WPA-PSK are the same. The only difference
between the two is that WPA-PSK uses a simple common password, instead of user-specific
credentials. The common-password approach makes WPA-PSK susceptible to brute-force
password-guessing attacks but it’s still an improvement over WEP as it employs an easier-to-
use, consistent, single, alphanumeric password.
Security Parameters Summary
Refer to this table to see what other security parameters you should configure for each
Authentication Method/ key management protocol type. MAC address filters are not
dependent on how you configure these security features.
Table 187 Wireless Security Relational Matrix
AUTHENTICATION
METHOD/ KEY
MANAGEMENT PROTOCOL
ENCRYPTION
METHOD ENTER
MANUAL KEY
ENABLE IEEE 802.1X
Open None No No
Open WEP No Enable with Dynamic WEP Key
Yes Enable without Dynamic WEP Key
Yes Disable
Shared WEP No Enable with Dynamic WEP Key
Yes Enable without Dynamic WEP Key
Yes Disable
WPA WEP No Yes
WPA TKIP No Yes
WPA-PSK WEP Yes Yes
WPA-PSK TKIP Yes Yes