WEP (wired equivalent privacy) is a standard network protocol that adds security to Wi-Fi and other 802.11 wireless networks. WEP was designed to give wireless networks the same level of privacy protection as a comparable wired network, but technical flaws greatly limit its usefulness. Newer, stronger protection standards have replaced WEP as the default for most modern networks.
WEP uses a data encryption scheme that is based on a combination of user- and system-generated key values. The original implementations of WEP supported encryption keys of 40 bits plus 24 additional bits of system-generated data, leading to keys of 64 bits in total length. To increase protection, these encryption methods were later extended to support longer keys, including 104-bit (128 bits of total data), 128-bit (152 bits total), and 232-bit (256 bits total) variations.
When deployed over a Wi-Fi connection, WEP encrypts the data stream using these keys so that it is no longer human-readable but can be processed by receiving devices. The keys are not sent over the network but are stored on the wireless network adapter or in the Windows registry.
Consumers who purchased 802.11b/g routers in the early 2000s had no practical Wi-Fi security options available other than WEP. It served the basic purpose of protecting a home network against login by neighbors.
Home broadband routers that support WEP commonly allow administrators to enter up to four different WEP keys into the router console so that the router can accept connections from clients set up with any one of these keys. Although this feature does not improve the security of any individual connection, it gives administrators added flexibility in distributing keys to client devices. For example, a homeowner may designate one key to be used only by family members and another key for visitors. With this feature, visitor keys can be changed or removed without modifying the family's devices.