The NPSA, or National Protective Security Authority, is the UK government body responsible for protective security guidance. In the context of cyber security, it is especially relevant where physical systems are connected to networks, such as CCTV, access control, alarms, and other building-security platforms. The NPSA also runs assurance schemes such as CAPSS, which assess whether products include appropriate cyber mitigations for physical-security environments.
NPSA matters because connected security gear can become part of an organization’s attack surface. Its guidance helps defenders choose products, configure them safely, and reduce the chance that a compromise in one system spreads to others. In real deployments, NPSA-style advice shows up in controls such as segmentation, restricted remote access, least privilege, patch management, and supplier assurance. Attackers often look for the opposite: exposed management interfaces, weak authentication, or poorly separated networks. NPSA guidance is designed to make those failures less likely.