ZyWALL 5/35/70 Series User’s Guide

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 270 Wireless Security Relational Matrix

AUTHENTICATION

ENCRYPTION

ENTER

 

METHOD/ KEY

ENABLE IEEE 802.1X

METHOD

MANUAL KEY

MANAGEMENT PROTOCOL

 

 

 

 

 

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

 

 

 

 

Roaming

A wireless station is a device with an IEEE 802.11 mode compliant wireless adapter. An access point (AP) acts as a bridge between the wireless and wired networks. An AP creates its own wireless coverage area. A wireless station can associate with a particular access point only if it is within the access point’s coverage area.

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Appendix H Wireless LANs