Layered Security

Layered security or defense in depth is the concept of applying a series of multiple, distinct layers of security controls and strategies to achieve greater overall protection. By employing combinations of security controls, the impact from the failure of any single security control can be minimized if not eliminated. Because the compromise of one security control will not be sufficient to compromise the entire system. Furthermore, security layering is concerned with separating system components by placing security controls between the layers, and hence preventing an attacker who has compromised one security layer from accessing other layers.