In an attempt to improve WEP's security a proposed modification (known as WEP2) uses 128 bits for the initialization vector (IV) value.

5. In an attempt to improve WEP's security a proposed modification (known as WEP2) uses 128 bits for the initialization vector (IV) value. In this case, estimate how many packets does it take "on average" for an attacker monitoring wireless communications to detect a pair of duplicated IVs (Initialization Vectors) with at least 50% probability, assuming the IV values are generated randomly when an AP (access point) and a wireless client (station) are communicating using WEP2's 128-bit IVs.