Introduced as a member of the original 802.11 standard ratified in 1997, its intention was to provide data confidentiality akin to that of a conventional wired network.  WEP, identifiable by its secret of 10 or 26 hexadecimal digits (40 or 104 bits), was at one time extensively in use and was frequently the first security choice presented to consumers by router configuration applications.
This tool relies on an active dictionary attack that tests millions of words to get the right key. Only one packet must begin an assault.
WepAttack is a WLAN open source Linux WEP key hacking tool for breaking 802.11 WEP keys using a wordlist based dictionary attack.