Wireless and Architecture Design

Wireless networks introduce a defensive challenge that wired networks do not face to the same degree: the signal itself is broadcast through the air and can be received by anyone within range, so encryption of the traffic itself has to substitute for the physical access control a wired network gets almost for free. The first widely deployed standard, Wired Equivalent Privacy (WEP), used the RC4 stream cipher but implemented it so poorly — reusing short initialization vectors in a predictable way — that its encryption could be broken with modest effort and readily available tools, and it is now considered wholly unsuitable for protecting any real network. Wi-Fi Protected Access (WPA) was introduced as an interim fix, keeping RC4 but wrapping it in the Temporal Key Integrity Protocol (TKIP) to rotate keys more frequently and close WEP's most glaring holes, while WPA2 replaced RC4 entirely with the much stronger AES cipher in CCMP mode, becoming the de facto standard for well over a decade.