The 802.11 standard - certification

• Open System Authentication (OSA)
• Shared Key Authentication (SKA)

In fact the open certification becomes lack of certification. Access point looks into every certification request. Possibillity of quick access network by device is a merit of open certification. After finishing of certification proces, the client may send and data receive. If the key of client is differ from key at access point, then client will not be able encipher and decipher of data frame correctly, and frames will be rejected by client as well as access point.

Unlike open certification, the shared key authentication demands that client station and access point has active WEP encryption and keys matched. Shared key authentication bases on similar assumption to open certification: the WEP keys are means of access control. Client and access point have to have matched keys. The difference between these two paterns is that in shared key variant client may not associate with access point untill it will not be configured correctly key.

The main weakness of WEP one might sum up, as follows:

• too short initialized vector IV and permissible repeat use of the same vector IV'
• lack of key update method – time of key usability is unlimited,
• lack of safety integrity checking – the CRC32 algorithm fits for errors detecting but it is not safety criptographically on account of its linearity'
• lack of any data source certification.

Reasumming, the WEP protocol should not be taken into consideration through designing securities in WLAN networks, even for applying of key rotation.