gatekeeper
n. countable C1 Advanced US //ˈɡeɪtˌkipɝ// UK //ɡˈeɪtkiːpɐ// gate·keep·er
n. a person or system that controls who can enter a place or who can get information. In computing, it is often a security tool that checks if a request is safe.
n. a person or entity that controls access to a resource, information, or location. In technical contexts, it refers to a security mechanism or software that filters and authorizes network traffic or data requests.
The security guard acts as a gatekeeper for the building.
In many organizations, the manager serves as a gatekeeper, deciding which projects receive funding and which do not.
Modern cybersecurity architectures often employ a gatekeeper at the network perimeter to filter out malicious traffic before it can reach internal servers or sensitive databases.
From gate + keeper.