Standard WEP has 16.7 million combinations.
KeyGuard has 281.474 trillion combinations.
KeyGuard is a proprietary, radio firmware based encryption scheme which provides per data packet rekeying using RC4 128bit WEP. KeyGuard eliminates the issues that have been identified with Static WEP because no single key is ever reused. A software algorithm in the radio card firmware accomplishes WEP key rotation. The algorithm needs a seed key that is the same at both the AP and the mobile device. The per packet hash function generates a new and unique, onetime key for each data packet.