This paper studies the coverage from the reverse standpoint, and addresses the issue how to design an "attacking track" to ensure that attacker drills through the region in security and speed (shortened form SS capability), where a number of sensors are deployed to detect illegal intruder. Not only does this track offer the attacker a right path, it also contributes to the user for the future deployment. A joint security and speed heuristic algorithm (SS algorithm) is proposed, which enjoys lower computational load than traditional algorithms. Furthermore, we give a practical definition of the parry probability (or un-detected probability) based on an interesting discerning process, and also introduce the novel metrics, called as integrated gain, to measure the SS capability.