Table-based Attack
The small space of possible initialization vectors allows an attacker to build a decryption table. Once he learns the plaintext for some packet, he can compute the RC4 key stream generated by the IV used. This key stream can be used to decrypt all other packets that use the same IV. Over time, perhaps using the techniques above, the attacker can build up a table of IVs and corresponding key streams. This table requires a fairly small amount of storage (~15GB); once it is built, the attacker can decrypt every packet that is sent over the wireless link.