Final answer:
A complementary security control is utilized to reinforce existing security measures or to add additional layers of security in support of enforcing security policies. They are an integral part of a defense-in-depth strategy, offering redundancy and broadened protection through multiple, overlapping layers of security.
Step-by-step explanation:
A complementary security control is deployed to provide various options to other existing controls to aid in enforcement and support of security policies. These controls can be any measures used in addition to, or in place of, another security control. They typically serve to provide a layered approach to security by adding additional safeguards that can reduce risk and enhance the effectiveness of the primary controls.
Examples of complementary security controls include additional firewalls, intrusion detection systems, or even physical security measures, such as security guards or surveillance cameras. They are crucial in maintaining a robust security posture as they provide redundancy – in case one control fails – and often address different aspects of security, which broadens the scope of protection.
Implementing complementary controls is a key concept in the defense-in-depth strategy, which advocates for multiple, overlapping layers of security to protect valuable data and systems.