The first of these was released in 1997 and
included a clause describing Wired Equivalency Privacy (WEP). WEP used the
RC4 stream cipher for encryption and a 24-bit initialization vector. The way WEP
uses RC4 and the short initialization vector, however, was shown to be exploitable
in 2001 by Scott Fluhrer, Itsik Mantin, and Adi Shamir.