Wireless Application Notes
Wireless Introduction
WEP Configuration (Wired Equivalent Privacy) Introduction
The 802.11 standard describes the communication that occurs in wireless LANs.
The Wired Equivalent Privacy (WEP) algorithm is used to protect wireless
communication from eavesdropping, because wireless transmissions are easier to
intercept than transmissions over wired networks, and wireless is a shared medium.
Everything that is transmitted or received over a wireless network can be
intercepted.
The WEP relies on a secret key that is shared between a mobile station (e.g. a
laptop with a wireless Ethernet card) and an access point (i.e. a base station). The
secret key is used to encrypt packets before they are transmitted, and an integrity
check is used to ensure that packets are not modified during the transmission. The
standard does not discuss how the shared key is established. In practice, most
installations use a single key that is shared between all mobile stations and access
points.
The WEP employs the key encryption algorithm, Ron's Code 4 Pseudo Random
Number Generator (RC4 PRNG). The same key is used to encrypt and decrypt the
data.
