The WEP Protocol

Brief description:
The sender and receiver share a secret key k.
In order to transmit a message M:
Compute a checksum c(M) [this does not depend on k]
Pick an IV v, and generate a keystream RC4(v,k)
XOR <M,c(M)> with the keystream to get the ciphertext
Transmit v and the ciphertext over the radio link
Upon receipt:
Use the transmitted v and the shared k to generate the keystream RC4(v,k)
XOR the ciphertext with RC4(v,k) to get <M',c'>
Check to see if c' = c(M')
If it is, accept M' as the message transmitted