What network security concept requires multiple layers of security controls to be placed throughout an IT infrastructure, which improves the security posture of an organization to defend against malic

Security through obscurity relies on hiding system details to deter attackers, which is a single weak measure rather than a strategy of layered controls distributed throughout infrastructure.

A Host-Based Intrusion Detection System is a single monitoring tool installed on individual endpoints, not a multi-layer security strategy spanning an entire IT infrastructure.

Defense in depth mandates distributing multiple security controls - such as firewalls, IDS, endpoint protection, and access controls - across every layer of an IT infrastructure. Each layer compensates for weaknesses in adjacent layers, so a bypass of one control does not compromise the entire environment. This strategy directly matches the question's description of layered controls improving an organization's security posture.

A Network-Based Intrusion Detection System monitors traffic at specific network points but is a single-layer detection tool, not a comprehensive strategy of multiple layered controls.