What is access control? Understanding access control components, types, and implementation
Access control is the fundamental security mechanism used to control who can access resources in a computing environment. It is a critical line of defense that enforces the principle of least privilege (PoLP), ensuring that a user or application is only granted the minimum level of permissions necessary to perform their required tasks, and nothing more. It works by using a three-step process: identification of the user, authentication to verify their identity (e.g., using a password or fingerprint), and authorization to determine what they are allowed to access based on their role or policies. This is a core security practice that protects organizations against unauthorized access, data theft, and other threats.
Key components of access control
The core components of access control define the framework for securely granting and denying resource access:
Identification: The process of identifying a user. This can be as simple as a username or account number, or a more complex identifier like a unique fingerprint. Identification alone provides no security but sets the stage for authentication.
Authentication: The process of verifying that the user is who they claim to be. This relies on the use of authentication factors, which are generally categorized as:
Knowledge factor: Something the user knows (e.g., password, PIN, or security question).
Possession factor: Something the user has (e.g., security token, smart card, or mobile phone for a one-time code).
Inherence factor: Something the user is (e.g., fingerprint, facial scan, or voice recognition).
To significantly enhance security, organizations implement multi-factor authentication (MFA), which requires a user to authenticate from two or more of these distinct factors.
Authorization: The process of determining the level of access a user is granted after they have been authenticated. This is based on organizational policies and a user's specific role, device, location, and access control models.
Policies and rules: The rules and guidelines that define who can access what resources and under what circumstances. These policies are enforced by the system to ensure security.
Why is access control important?
Implementing a strong access control system delivers crucial benefits to an organization:
Protects sensitive data
It prevents unauthorized individuals from stealing or accessing confidential information. It ensures data is accessible only to users with a justifiable business need.
Reduces risk
By enforcing the PoLP, access control drastically minimizes the potential damage caused by both accidental errors and malicious intent.
Enforces compliance
It helps organizations comply with industry regulations and standards that require secure handling of data. Examples include:
HIPAA (healthcare): Requires strict controls over protected health information.
GDPR (European Union): Requires technical and organizational measures to protect personal data.
PCI DSS (credit cards): Requires controls to protect cardholder data environment.
Protects physical locations
It is used to control entry into physical areas, like corporate headquarters, data centers, and server rooms, using keycards, biometric scanners, and smart locks.
Types of access control
There are various types of access control models, each helping admins restrict access in a unique way. Below are the four main methods, followed by several specialized models:
Role-based access control (RBAC): This is the most common model. Access is provided based on job roles (e.g., finance manager or database administrator). Users are assigned roles, and roles are assigned permissions. This simplifies management as permissions are not assigned to individual users.
Discretionary access control (DAC): The owner of the resource, like a file or folder, is responsible for setting permissions for other users. This is highly flexible but difficult to manage in large organizations and prone to security errors.
Mandatory access control (MAC): A non-discretionary system where the operating system or security kernel enforces access based on predefined security levels assigned to users and objects. This is mostly used in environments requiring the highest level of security, like government and military systems.
Attribute-based access control (ABAC): A dynamic model that grants access based on a set of attributes associated with the user, the resource, the action requested, and the environment. This approach offers the highest granularity and flexibility.
Specialized access control models:
Identity-based access control (IBAC): A simple model where access is tied directly to the specific authenticated identity of the subject, rather than their role or attributes. This model is generally less scalable than RBAC for large organizations.
History-based access control (HBAC): Access rights are dynamic and based on the historical context and sequence of actions previously performed by the subject. For instance, access might be temporarily revoked if a user performs a sequence of high-risk operations.
Risk-adaptive access control (RAdAC): An advanced model where authorization is granted or denied based on a real-time risk calculation. Factors like device health, location deviation, and behavioral abnormalities contribute to the risk score.
Rule-based access control (RuBAC): Access is granted or denied based on a set of defined, static rules that evaluate specific conditions about the user, the resource, and the environment. Rules are typically managed centrally. This works best for stable environments with clear hierarchies.
Organization-based access control (OrBAC): A conceptual model that lets organizations define security policies in simple, business-friendly terms. Instead of working directly with technical permissions, it uses concepts like roles (who can act), activities (what actions they can perform), and views (what resources they apply to). These policies are later translated into more detailed technical rules.
How to implement a strong access control system
Building a robust access control system requires a strategic, layered approach based on the following best practices:
Establish least-privilege policies: Define clear access rules and enforce the PoLP, ensuring users and systems only have the minimum access necessary for their function.
Secure identity verification: Implement MFA for all sensitive resources to significantly mitigate the risk of successful attacks from compromised credentials.
Centralize management and modeling: Utilize a centralized identity and access management (IAM) system and select the appropriate authorization model for efficient administration and scalability. Tools like access packages and access catalogs should be used to standardize and govern resource assignment for efficient administration.
Continuous verification: Adopt a Zero Trust architecture, which requires continuous verification of every access request, backed by regular security auditing and log monitoring for suspicious activity.
What's the right access control system for you?
Today’s organizations must balance security, productivity, and compliance. While solutions like VPNs, provisioning tools, and password managers help enforce access control, managing them separately can lead to inconsistencies, manual errors, and security gaps. A centralized, integrated approach ensures policies are applied uniformly across your directory environment.
ManageEngine ADManager Plus, a comprehensive IAM solution for Active Directory and Microsoft 365, helps enforce least privilege, automate repetitive tasks, and maintain a complete audit trail to meet regulatory standards. Some of its features include:
User provisioning and deprovisioning: Automate the creation of user accounts, assignment to the correct groups, and provisioning of required permissions during onboarding, and instantly remove all access upon offboarding.
RBAC: Allows you to quickly delegate access based on a user’s role rather than manually setting individual permissions, minimizing configuration errors.
Auditing and compliance reporting: Generate comprehensive reports on user permissions, group memberships, and logons. This is critical for continuous monitoring and meeting regulatory requirements (e.g., HIPAA or the GDPR) by providing a clear, auditable trail of all access control activity.
Group Policy management: Centrally manage and modify GPOs to enforce consistent security and access rules across your environment without relying on manual effort or native complexity.
Password and account control: Reset passwords, unlock accounts, and enforce security settings in bulk to maintain healthy and secure user accounts.
Workflow-based access governance: Build custom approval workflows for user creation, permission changes, and access requests. This ensures every access modification is reviewed, approved, and documented before being applied.
Streamline access control with ADManager Plus
FAQ
1. What are the four types of access control?
The four main types of access control are:
Discretionary access control: The owner of a resource determines who can access it.
Mandatory access control: Access is granted based on security clearances (labels) and resource classifications.
Role-based access control: Access is assigned to users based on their defined role within the organization (e.g., manager or developer).
Attribute-based access control: Access is granted dynamically by evaluating a set of attributes belonging to the user, resource, and environment.
2. What is the difference between authentication and authorization?
Authentication verifies the identity of a user or system (e.g., checking a password or biometrics) to confirm they are who they claim to be. Authorization determines what that authenticated user is permitted to do or access on the system (e.g., read, write, or edit a file). Think of authentication as showing your ID to get into a building and authorization as the keycard dictating which rooms you can enter.
3. What is the PoLP?
The principle of least privilege (PoLP) is a core security concept requiring that users, processes, or systems be granted only the minimal access rights and resources necessary to perform their required tasks, and nothing more. This minimizes the attack surface and potential damage from accidental error, insider misuse, or a security breach where an attacker gains a user's credentials.
4. What is Zero Trust and how does it relate to access control?
Zero Trust is a security model based on the principle of "never trust, always verify," meaning no user or device, whether inside or outside the network perimeter, is trusted by default. It fundamentally enhances access control by requiring continuous and dynamic verification of every access request based on identity, device posture, and context before granting the least necessary access. This contrasts with traditional models that granted broad trust once a user was inside the network.