Why do you need to capture five to ten million packets in order to crack WEP with AirSnort?

A.
All IVs are vulnerable to attack

B.
Air Snort uses a cache of packets

C.
Air Snort implements the FMS attack and only encrypted packets are counted

D.
A majority of weak IVs transmitted by access points and wireless cards are not filtered by contemporary wireless manufacturers

Explanation:
Since the summer of 2001, WEP cracking has been a trivial but time consuming process. A few tools, AirSnort perhaps the most famous, that implement the Fluhrer-Mantin-Shamir (FMS) attack were released to the security community — who until then were aware of the problems with WEP but did not have practical penetration testing tools. Although simple to use, these tools require a very large number of packets to be gathered before being able to crack a WEP key. The AirSnort web site estimates the total number of packets at five to ten million, but the number actually required may be higher than you think.