Quick Guide to WiFi

Introduction

Software

"Hélas le support du i802.11a n'avait aucun intérêt pour nous autres européens, cette norme n'ayant pas du tout décollée dans nos contrées."

"Ability to toggle between Intel PROSet/Wireless and Microsoft Windows* XP Wireless Zero Configuration Service"

WEP

Wired Equivalent Privacy

"Several serious weaknesses were identified by cryptanalysts, and WEP was superseded by Wi-Fi Protected Access (WPA) in 2003, and then by the full IEEE 802.11i standard (also known as WPA2) in 2004. Despite the weaknesses, WEP provides a level of security that can deter casual snooping." http://en.wikipedia.org/wiki/Wired_Equivalent_Privacy

WPA

Wi-Fi Protected Access

WPA2: uses the Advanced Encryption Standard, instead of RC4, which was used in WEP and WPA

"WPA is designed for use with an 802.1X authentication server, which distributes different keys to each user; however, it can also be used in a less secure "pre-shared key" (PSK) mode, where every user is given the same passphrase. The Wi-Fi Alliance calls the pre-shared key version WPA-Personal or WPA2-Personal and the 802.1X authentication version WPA-Enterprise or WPA2-Enterprise.

Data is encrypted using the RC4 stream cipher, with a 128-bit key and a 48-bit initialization vector (IV). One major improvement in WPA over WEP is the Temporal Key Integrity Protocol (TKIP), which dynamically changes keys as the system is used. When combined with the much larger IV, this defeats the well-known key recovery attacks on WEP."

"WPA uses 802.1x and Extensible Authentication Protocol (EAP) as the base of its authentication mechanism, but implements two authentication modes. In its "enterprise" level implementation, WPA's authentication will require a central authentication server (typically RADIUS) to authenticate each user on the network before they join it.

But since the authentication server requirement would never work in a consumer / SOHO WLAN because of the cost an complexity, WPA also provides a simplified form that allows the use of manually entered keys or passwords instead. This mode - called Pre-Shared Key (PSK) - only requires a single password entered into each WLAN node (Access Points, Wireless Routers, client adapters, bridges). Once the password is entered, WPA's TKIP mechanism takes over, generating and changing the WEP keys automatically." http://www.tomsnetworking.com/2002/11/01/wpa_/page4.html