Layered Security

Layered security, also known as layered defense, describes the practice of combining multiple mitigating security controls to protect resources and data.

The term bears some similarity to defense in depth, a term adopted from a military strategy that involves multiple layers of defense that resist rapid penetration by an attacker but yield rather than exhaust themselves by too-rigid tactics. As the incursion progresses, resources are consumed and progress is slowed until it is halted and turned back. The information assurance use of the term "defense in depth" assumes more than merely technical security tools deployment; it also implies policy and operations planning, user training, physical access security measures, and direct information assurance personnel involvement in dealing with attempts to gain unauthorized access to information resources. Within a defense in depth security strategy, layered security is regarded by some as merely a delaying tactic used to buy time to bring security resources to bear to deal with a malicious security cracker's activities.