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How Access Control Systems Work

October 4, 2023

Too busy to read? Here’s a summary:

  • An access control system works by assessing credential data and matching it to site authorizations. Access is allowed if a credential meets preprogrammed criteria or is matched with a site’s authorization list.
  • Discretionary access control (DAC), mandatory access control (MAC), and role-based access control (RBAC) are popular methods for assigning site privileges to credential holders.

Access control systems range from those using simple keycard readers to complex biometric systems. What they all have in common is the responsibility for regulating site access by verifying credentials and then granting or denying access based on predefined criteria or a credential’s particular site authorizations.

Components and Steps of Most Access Control Systems

Access Control Software: Access control software allows administrators to manage access permissions, monitor activities, and generate reports. Access control software can be hosted on-site or on the cloud.

Credentials: Access control systems require credentials for identity verification. The credentials come in many forms, including knowledge-based credentials (requiring the input of a PIN or passcode on a keypad), card credentials (embedded with chips containing unique identification numbers), mobile credentials (requiring signals transmitted by smartphones), and biometric credentials (which requires the presentation of an individual’s unique biological data, such as that contained in fingerprints and irises).

Antennas: Small antennas inside cards and phones receive and transmit signals to and from antennas inside door readers. While tiny, data transmission through these antennas is crucial to entry processes.

Readers: These devices are installed at access points and detect and read unique identification numbers entered on keypads or transmitted by cards, fobs, smartphones, and other credentials. Biometric access control systems, on the other hand, scan or visually capture fingerprints, irises, faces, and other biological identifiers.

Control Panel: A centralized control panel is the brain of most access control systems. It receives a credential’s data from the reader in order to cross-check it against the panel’s stored authorizations or authorization criteria.

Electronic Locks: If the control panel finds a match between a credential and site authorizations, it will transmit an electronic signal to unlock the access point temporarily.

How Site Authorizations Are Managed

Access control systems enable administrators to assign site access privileges using different rules. The three most common approaches to assigning access permissions are known as discretionary access control (DAC), mandatory access control (MAC), and role-based access control (RBAC).

Discretionary Access Control (DAC)

Discretionary Access Control (DAC) refers to an access control system in which a site manager or other authority can grant or deny access to specific resources based on their judgment.

How DAC Works:

In DAC, every resource has an owner who can grant access permissions to other users or groups.

Advantages of DAC:

  • Offers flexibility as permissions can be easily modified by the owner.
  • Suitable for environments where constant changes in access rights are required.

Disadvantages of DAC:

  • It can be less secure as a malicious program running under an owner's privilege level can potentially modify permissions.
  • Relies heavily on the judgment of individual users, which can result in mistakes, inconsistencies, and security breaches.

Mandatory Access Control (MAC)

Mandatory Access Control (MAC) is a more rigid permission model than DAC. In MAC, access to resources is granted based on predefined security policies set by central system administrators.

How It Works:

Resources are assigned classification labels, and users can access resources only if they have adequate clearance.

For example, a military installation may have areas or information marked "Top Secret" and "Confidential." A user can access such resources only if their security clearance matches or exceeds the classification of the resource or area.

Advantages of MAC:

  • Provides a higher level of security as permissions strictly adhere to centrally administered policies.
  • Reduces risks like data leakage and unauthorized access.

Disadvantages of MAC:

  • Less flexible as changes to access permissions require modifying centralized policies.
  • It is more complex to implement and manage than most other systems.

Role-Based Access Control (RBAC)

Role-Based Access Control (RBAC) refers to an access control model in which permissions are granted based on the role a user holds within an organization.

How RBAC Works:

Roles are defined based on job functions or tasks within an organization. Permission to access resources is assigned to these roles rather than to individuals.

For example, in a role-based access control system, an HR Manager role might have access to employee records, while a Finance Manager role might have access to sensitive financial data.

Advantages of RBAC:

  • Simplifies permission management as administrators only need to manage roles, not individual user permissions.
  • Provides a clear separation of duties and ensures that users only access data relevant to their job function.
  • Easily scalable for large organizations.

Disadvantages of RBAC:

  • Initial setup can be time-consuming because roles and permissions need to be clearly defined ahead of time.
  • Might not be suitable for smaller businesses and organizations, especially those with overlapping job functions.

Benefits of Using an Access Control System

Access Control Image

Understanding how an access control system works is just the tip of the iceberg. The real magic lies in the many benefits access control systems provide.

Enhanced Security

At its core, the primary purpose of an access control system is to bolster security. By regulating who can and cannot enter a particular area or access specific data, these systems:

Minimize Risks: They significantly reduce the chances of unauthorized individuals gaining access to sensitive areas or information.

Tailored Access: Administrators can set permissions based on individual or role-specific needs, ensuring that people only access the areas and tools they need to perform their duties.

Immediate Response: In the event of a lost or stolen access credential, the system enables instant credential deactivation to prevent potential misuse.

Ease of Management

Modern access control systems can connect to the Internet and be integrated with other devices.

Unified Control: Instead of managing multiple keys or access cards, administrators can oversee all access points and permissions on a single, easy-to-use dashboard.

Flexibility: With the exception of mandatory access control (MAC) approaches, it’s easy to grant, modify, or revoke access in real time in response to changes in roles and responsibilities.

Remote Management: Modern access control systems allow for remote access, meaning administrators can manage permissions and monitor access events even when they're not on-site.


While there's an initial investment involved in setting up an access control system, the long-term savings are substantial.

Reduced Personnel Costs: With automated access control in place, there's less reliance on physical security personnel to guard entrances and check credentials.

Fewer Lock Replacements: Traditional keys, when lost, often mean changing locks. With electronic systems, a lost credential can be deactivated with a click.

Audit Trails

One of the often-overlooked benefits of electronic access control is the ability to log and monitor access events.

Detailed Logs: Every entry, exit, and access attempt can be logged with details like time, date, and user identity.

Compliance and Review: For many heavily regulated industries, these automated logs adhere to regulations that require audit trails and periodic system reviews.

Forensic Utility: In the unfortunate event of a security incident, an audit trail can aid investigations by providing a record of who was where and when.

Mammoth Security and Your Access Control Solution

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Our team at Mammoth Security knows the ins and outs of commercial-grade access control. For assistance implementing a system that cost-effectively meets the needs of your organization, please contact us today! Just fill out the simple form below. We’ll quickly reach out to schedule your free site survey and security assessment.




Biometric systems are among the most secure access control systems because they rely on unique physical characteristics that can’t be lost, stolen, or shared. However, no system is foolproof, and it's essential to keep access control software updated to stay ahead of cyber threats.

Like any digital system, access control systems can be vulnerable to hacking. Regular software updates and using multi-factor authentication can reduce the risk.

Review and update your access control system annually or whenever there are significant changes in personnel or infrastructure.

While both are security measures, access control regulates entry, whereas alarm systems alert users to potential security breaches.

It can be, depending on the systems in question. However, with proper planning and expert help, the transition can be smooth.



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