Security has been one of the major deficiencies in Wi-Fi, though better encryption systems are now becoming available. Encryption is optional in Wi-Fi, and three different techniques have been defined. These techniques are given here:
Wired Equivalent Privacy (WEP):
An RC4-based 40-or 104-bit encryption with a static key.
Wi-Fi Protected Access (WPA):
This is a new standard from the Wi-Fi Alliance that uses the 40 or 104-bit WEP key, but it changes the key on each packet. That changing key functionality is called the Temporal Key Integrity Protocol (TKIP).
The IEEE is finalized the 802.11i standard, which is based on a far more robust encryption technique called the Advanced Encryption Standard. The Wi-Fi Alliance designate products that comply with the 802.11i standard as WPA2.
However, implementing 802.11i requires a hardware upgrade.