What is Access Control in cybersecurity?

Access control security encompasses the tools and processes that restrict access to resources in an IT infrastructure. Access control systems define the rules and policies that ensure only authorized entities are allowed to access and perform operations on specific networks or applications.

Access control enforces both authentication and authorization policies to regulate access. Authentication verifies the identity of the user, whereas authorization determines whether the user has the privileges to interact with the asset they are trying to access.

For example, if an employee swipes their card to enter an office building, the access control system authenticates them by verifying the access card’s credentials. Once authenticated, the system authorizes the employee's access based on their role or clearance level. If the employee has the required privileges, the door will unlock, and they will be allowed to enter.

Access control is a crucial part of cybersecurity as it protects against unauthorized access, privilege escalation and potential breaches. By implementing robust access control policies, organizations can improve their overall security posture and reduce their attack surface.

There are several types of access control models, including:

RBAC systems assign permissions and privileges to users based on their roles and responsibilities. For example, a software engineer may have access to the source code repository, the CI/CD tool and the staging virtual machines. On the other hand, a production engineer may have exclusive access to the production virtual machines.

RuBAC uses a set of predefined rules to control access to sensitive information and applications. The rules contain different conditions that are evaluated to make access decisions. For example, an administrator could define a rule that allows only users from a specific department and with a specific designation to access an application.

MAC tools determine access based on security labels assigned to both users and resources. For example, if user X wants to perform some operations on an application Y, a MAC tool ensures that:

• The user’s access policy includes privileges to access and interact with application Y.
• The application Y’s policy explicitly allows the user (or their group) to access it and perform desired operations.

MAC policies significantly reduce the attack surface by preventing unauthorized operations, even when someone has access to an application.

DAC is a flexible model that allows resource owners to determine who has access to their resources. It's commonly used in file systems where owners control access to their files and folders. It’s worth noting that DAC can also introduce vulnerabilities, as access control decisions are made by individual users who may not be aware of the overall security landscape.

Access Control Lists (ACLs) are another way to implement access control. ACLs are typically defined at the resource level. For example, you can define an ACL to restrict access to an S3 bucket on AWS. The ACL policy includes the name of the resource owner, along with details of other users who are allowed to interact with the bucket.

ABAC systems make access decisions based on user attributes, such as job title, department, location and time. For example, an administrator can use ABAC to restrict access to a sensitive database to members of the "production" user group, only when they are connected to the office network.

To choose the right access control model for your organization, carefully evaluate your security expectations and compliance needs. You may even choose a combination of different models if it makes sense. Several IAM solutions, including Access Management (AM), Privileged Access Management (PAM) and Identity Governance and Administration (IGA) systems offer different ways to implement fine-grained access control.

1. Start by performing a thorough assessment of your security posture. Answer questions like: “Which assets are the most security critical?” “How will I implement strong authentication?” “How many roles do I need across the organization?” “Which security frameworks do I need to comply with?”
2. Based on the results of the previous step, choose the type of access control system that you want to go with.
3. Evaluate available options in the market and select the one that aligns with your requirements. Consider factors like scalability, adaptability, compatibility (especially with legacy systems) and ease of use.
4. Deploy and install the access control system. If you choose a software as a service (SaaS) access control system, you should be able to skip this step.
5. Integrate the access control system with all the networks and applications on your infrastructure.
6. Enroll users and their credentials (e.g., biometrics, access keys) for authentication. Consider setting up multi-factor authentication (MFA).
7. While adhering to the principle of least privilege, assign access rights and permissions to roles, users and user groups.
8. Thoroughly test the system to ensure that it’s accurately enforcing all the configured policies. If possible, simulate different scenarios to identify any potential security gaps.
9. Train your employees and administrators on how to effectively use the access control system.
10. Implement a continuous monitoring system to detect suspicious behavior and stay compliant with security standards and regulations.

Access control systems offer several benefits, including:

Access control acts as a resolute layer of security that protects assets, applications, data and networks from unauthorized access. It significantly reduces the chances of data leaks, privilege escalation, malware and other security incidents.

Access control systems offer a centralized dashboard to define and enforce security controls across the entire infrastructure. This streamlines the process of granting and revoking privileges, freeing up administrative staff to focus on more productive tasks.

Access control systems pave the path for compliance with different regulations that mandate access controls, like HIPPA and PCI DSS. Moreover, access control goes hand in hand with Zero Trust, a requirement in several security frameworks.

A good access control system enables administrators to tailor authentication and authorization policies to match the organization’s specific needs. They enjoy fine-grained control over who can access what, and under which circumstances. This ensures adherence to the principle of least privilege, which decreases the overall attack surface of an organization.

Access control systems generate detailed audit trails and logs, which can be used to track access events. By tracking and monitoring access events, organizations can detect anomalous behavior, identify policy flaws and prevent potential breaches.

Access control systems can integrate seamlessly with other security tools to form a cohesive security stack. For example, they can be integrated with an Intrusion Detection System (IDS) to initiate an automatic system lockdown in the event of a breach.