How exactly would one use this key nefariously? It seems to do so would require a whole chain of capabilities. In any case it would make sense to have multipl

How exactly would one use this key nefariously? It seems to do so would require a whole chain of capabilities. In any case it would make sense to have multiple master keys...say use a different master key for each batch of so many cards.. then if one key was compromised it wouldn't affect 12M cards.