WEP means: Wired Equvalent Privacy
it's an old encryption
uses an algorythm called RC4
still used in some networks
can be cracked easily
How Encryption works
each Package is encrypted via a unique Keystream
Random Initialization Vector (IV) is used to generate the Keystreams
The IV is only 24 bits
IV + (password) Key = keystream
Because the router already knows the (password) Key WLAN devices just need to send the IV
