Definition: WEP is a protocol that adds security to wireless local area networks (WLANs) based on the 802.11 Wi-Fi standard. WEP is an OSI Data Link layer (Layer 2) security technology that can be turned “on” or “off.” WEP was designed to give wireless networks the equivalent level of privacy protection as a comparable wired network.
WEP is based on a security scheme called RC4 that utilizes a combination of secret user keys and system-generated values. The original implementations of WEP supported so-called 40-bit encryption, having a key of length 40 bits and 24 additional bits of system-generated data (64 bits total). Research has shown that 40-bit WEP encryption is too easy to decode, and consequently product vendors today employ 128-bit encryption (having a key length of 104 bits, not 128 bits) or better (including 152-bit and 256-bit WEP systems).