An access control system controls who can enter a building or area, when they can enter, and under what conditions. It replaces physical keys with credentials, readers, and software that grant or deny entry based on rules set by the organization. Most mid-to-large organizations use access control to manage entry across multiple sites, reduce the risk of lost or copied keys, and create a record of who accessed what and when.
Key takeaways
- An access control system decides who can enter a space, when, and under what conditions, replacing physical keys with credentials, readers, controllers, and management software.
- It works by presenting a credential at a reader, checking it against permissions stored on a controller, and granting or denying access in real time.
- Systems are grouped by deployment model (on-premises, cloud-based, or hybrid) and permission model (DAC, MAC, RBAC, or ABAC), with RBAC the most common in enterprise.
- Access control also provides real-time visibility, instant credential revocation, audit trails, and integration with video, intruder, perimeter, and HR systems. Gallagher Security's Command Centre manages this from a single platform.
How does an access control system work?
An access control system works through identification, authentication, and authorization stages. A credential is presented at a reader, the controller checks it against stored permissions, and access is granted or denied in real time.
Three components handle this process. The reader captures the credential (a card, fob, mobile signal, or biometric scan) at the door. The controller makes the access decision by checking that credential against rules held locally, which means a door keeps working even during a network outage. The management software is where administrators set permissions, build schedules, and review audit logs of every access event.
What are the key components of an access control system?
A modern access control system consists of five components that work together to manage and record who enters protected spaces.
Credentials
The credential proves identity at the door. Common types include cards and fobs, PINs, mobile credentials, and biometrics.
Readers
Readers capture the credential and pass that information to the controller. Reader types vary by credential format, from card readers to mobile-enabled terminals.
Controllers
Controllers process the access decision, checking the presented credential against stored rules and logging the outcome.
Management software
Management software is where permissions are configured, schedules are built, and reports are generated for audits or investigations.
System integration
Integration connects access control to other building and security systems, including video, perimeter security, intruder alarms, and HR platforms, so access events trigger or inform actions elsewhere.
What types of credentials can an access control system use?
Access control systems support four main credential types, each with a different balance of convenience and security.