Should this not be the case, and the attacker is able to determine some factor that may influence how the key was selected, the search space (and hence also the search time) can be significantly reduced.
もしそうでなく、しかも鍵の選択方法に影響を与え得る要因を攻撃者が特定することができるなら、探索空間 (および探索時間) は著しく縮小する。