Chapter 6 Deploying Wireless Networks for FortiOS 5.0 : Introduction to wireless networking : Security : Encryption
  
Encryption
Wireless networking supports the following security modes for protecting wireless communication, listed in order of increasing security.
None — Open system. Any wireless user can connect to the wireless network.
WEP64 — 64-bit Web Equivalent Privacy (WEP). This encryption requires a key containing 10 hexadecimal digits.
WEP128 — 128-bit WEP. This encryption requires a key containing 26 hexadecimal digits.
WPA — 256-bit Wi-Fi Protected Access (WPA) security. This encryption can use either the TKIP or AES encryption algorithm and requires a key of either 64 hexadecimal digits or a text phrase of 8 to 63 characters. It is also possible to use a RADIUS server to store a separate key for each user.
WPA2 — WPA with security improvements fully meeting the requirements of the IEEE 802.11i standard. Configuration requirements are the same as for WPA.
For best security use the WPA2 with AES encryption and a RADIUS server to verify individual credentials for each user. WEP, while better than no security at all, is an older algorithm that is easily compromised. With either WEP or WAP, changing encryption passphrases on a regular basis further enhances security.