Which term represents the security strategy of distributing security controls across multiple layers rather than depending on a single perimeter?

Which term represents the security strategy of distributing security controls across multiple layers rather than depending on a single perimeter?

• A. Perimeter security
• B. Defense in depth
• C. Zero trust
• D. Segmentation

Answer: (B)

Defense in depth means distributing security controls across multiple layers rather than relying on a single perimeter. By layering protections—from network boundaries and host hardening to access controls, application security, data protection, monitoring, and incident response—you create overlapping safeguards. If one layer is breached or fails, others still stand in the way, reducing the chance that an attacker can reach sensitive assets and improving detection and response opportunities. This approach also mitigates the risk of a single point of failure tied to any one boundary. Perimeter security focuses on defending the boundary itself, which can be bypassed. Zero trust emphasizes never implicitly trusting anywhere inside or outside the network and continuously verifying identities and device posture, which is a broader philosophy that informs layered protection but isn’t the label for the layered, multi-layer strategy itself. Segmentation is a technique used within defense in depth to limit lateral movement by dividing networks into zones, but on its own it’s just one layer among many.

Defense in depth means distributing security controls across multiple layers rather than relying on a single perimeter. By layering protections—from network boundaries and host hardening to access controls, application security, data protection, monitoring, and incident response—you create overlapping safeguards. If one layer is breached or fails, others still stand in the way, reducing the chance that an attacker can reach sensitive assets and improving detection and response opportunities. This approach also mitigates the risk of a single point of failure tied to any one boundary.

Perimeter security focuses on defending the boundary itself, which can be bypassed. Zero trust emphasizes never implicitly trusting anywhere inside or outside the network and continuously verifying identities and device posture, which is a broader philosophy that informs layered protection but isn’t the label for the layered, multi-layer strategy itself. Segmentation is a technique used within defense in depth to limit lateral movement by dividing networks into zones, but on its own it’s just one layer among many.