What is Access Control? Components and Types

Access control is the security framework that determines who or what can access systems, applications, and data, and under what conditions. As digital transformation has reshaped modern IT environments, traditional network boundaries have largely disappeared. When applications were hosted on-premises, firewalls acted as clear, centralized gatekeepers. The shift to cloud computing, remote work, and distributed systems has changed that model entirely.

Understanding access control basics

So what are access controls? The simplest definition of access control is a system that restricts access to resources based on predefined rules and user credentials. Access control is a core component of information security that regulates access rights across your entire organization. 

At its core, an access control system determines who is allowed to access specific resources, what level of access they receive, and under what conditions they can interact with your data. Put simply, access control involves verifying identities and enforcing rules that determine who can perform what actions.

The goal of access control is straightforward: the right people gain access to the right resources at the right time, while everyone else is denied access. This sounds simple, but execution gets complicated quickly.

How credentials and permissions work

Every access management system operates by assigning credentials to identities, whether human users or digital entities, such as service accounts. These credentials include a username and password, an access card for physical access control, or biometric data. Electronic access control systems extend these principles to doors, turnstiles, and other physical entry points. Once authenticated, the security system grants permissions based on access policies.

We’ve seen organizations struggle with this because it spans both logical access control (digital systems) and physical access control (buildings, data centers, server rooms). An effective identity and access management program addresses both dimensions.

Physical access considerations

When we talk about access control, many people think only about digital systems. But controlling access to a physical location remains just as important. Examples of physical access control include badge readers at office entrances, biometric scanners at data center doors, and mantraps that prevent tailgating. Access control is used in virtually every facility housing sensitive equipment or information.

Modern access control systems integrate both physical and logical controls into a unified platform. When an employee badges into a building, the system might also trigger their workstation to unlock or enable their network access for that location.

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The main types of access control models

Understanding the main types of access control models helps you select the most suitable approach. There are four main types of access control that organizations commonly deploy, and each access control model offers different levels of security and flexibility. Selecting between these types of access management depends on your industry, regulatory requirements, and risk tolerance.

Discretionary access controls

Discretionary access control (DAC) gives resource owners the power to decide who can access their assets. Under this model, if you own a file or folder, you can provide access to others, grant access to colleagues, and change security attributes as you see fit. You can even delegate authority, allowing them to extend access to other users in turn.

Think about how Google Drive works. When you create a document, you control who can edit, comment, or view it. You can share that document with anyone and give them the same editing privileges you have. This flexibility makes DAC intuitive, but it can also be potentially risky in enterprise environments where tighter data access control is required.

Mandatory access controls

Mandatory access control (MAC) takes a more restrictive approach. Under MAC, a central authority regulates access rights for all users and resources uniformly, placing strict limitations on what people can do. Users cannot pass information to unauthorized parties, give their privileges to others, or change security attributes on objects.

Government and military organizations often rely on MAC because it prevents data from flowing to lower security levels. Access is granted only when users have proper clearance and a legitimate need to know. The tradeoff is reduced flexibility, as even resource owners must follow rules established by system administrators.

Role-based access control

Role-based access control (RBAC) has become the most common access control model in enterprise environments. RBAC assigns access based on job functions rather than individual identities. The system grants access based on the role you hold, not who you are as an individual. 

For instance, everyone in marketing gets access to the CRM, social media accounts, and marketing folders. Everyone in finance gets access to accounting systems and financial reports. This model streamlines access control in work environments by logically grouping permissions.

This approach simplifies user access controls at scale. When someone joins the company, you assign them a role, and users are granted automatic access to everything that role includes. Organizations managing third-party vendor access find RBAC particularly useful for onboarding and offboarding external partners.

The challenge with RBAC emerges as organizations grow. Roles multiply, exceptions accumulate, and suddenly you’re managing hundreds of role definitions with overlapping permissions.

Attribute-based access control

Attribute-based access control (ABAC) offers the most granular approach. This model uses a combination of attributes to make access decisions in real-time:

• Organizational factors like job title and department
• Action attributes like read or write permissions
• Environmental factors like time of day and geolocation
• Resource attributes like data classification

ABAC enables organizations to set dynamic access control policies that respond to context. A contractor might be allowed to access project files only during business hours and from approved locations. Modern access control technology enables these dynamic decisions to be made at scale. Organizations can build sophisticated workflows based on access control rules that adapt to changing conditions.

This contextual approach aligns well with zero trust security principles, where every access request gets evaluated based on multiple factors rather than assuming trust based on network location alone.

Why access control matters more than ever

Cloud migration has transformed the way we protect information. Most employees now use public internet connections to access data and applications. Each access point represents a potential threat vector. The security risk of unauthorized access grows with every new connection point. Protecting access to information has never been more challenging.

The expanding attack surface

The growth of Internet of Things devices compounds this challenge. Printers, sensors, building systems, and countless other devices need access to systems and data stores. This expanding supply chain cyber risk extends to every connected vendor in your ecosystem.

This is why credential-based attacks have become so prevalent. Every time you assign a username and password to a human or digital identity, you create another potential entry point. Consider the access risks from:

• Employees and contractors
• Network devices and IoT sensors
• Service accounts and robotic process automations

Each of these identities can be compromised if not properly managed.

The credential theft challenge

Credential theft attacks are notoriously difficult to detect because malicious actors use legitimate credentials. Your security system sees what appears to be a valid user performing authorized actions. Establishing strict user access controls and enforcing the principle of least privilege creates a more robust defense.

Our STRIKE Team continuously monitors the dark web for leaked credentials and compromised access that could affect your organization or your vendors.

How organizations implement access control

Building an effective access control system requires multiple layers of protection working together. The access control features you implement should address authentication, authorization, and ongoing monitoring.

Authentication and identity management

Authentication confirms that users are who they claim to be before they gain access to the resource they’ve requested. Strong authentication typically combines multiple factors:

• Something the user knows, like a password
• Something the user has, like a smartphone or hardware token
• Something the user is, verified through biometrics like fingerprints or facial recognition

Only after successful verification is a user granted access to a system or application. The goal is to restrict access to authorized users only.

We’ve observed that many users reuse passwords across personal and professional accounts, creating significant risk. When credentials leak from one breach, attackers attempt to use those same combinations against corporate systems. Multi-factor authentication adds a critical layer that can prevent unauthorized access even when passwords are compromised.

Identity management extends beyond simple authentication to encompass the entire lifecycle of user identities: provisioning new accounts, managing role assignments, conducting periodic access reviews, and deprovisioning accounts when employees leave.

Authorization and the principle of least privilege

Authorization determines what authenticated users can actually do. Once access rights are granted, users have access to perform specific actions within the systems they can reach. The principle of least privilege dictates that users should be granted only the minimum access rights necessary to perform their job functions. Nothing more. The process of limiting access to only what’s necessary significantly reduces your attack surface.

Implementing the principle of least privilege in complex environments is more complicated than it sounds. Your CRM alone might have dozens of permission sets controlling access to contacts, opportunities, reports, and administrative functions. Configuring the appropriate level of access for every user requires significant effort. Sometimes users only need access to certain features within a larger application, not the entire system.

Excess access creates real security risks. Attackers who compromise an over-privileged account gain immediate access to more resources. As employees move between departments, they often accumulate historic permissions from previous roles, creating privilege creep.

Segregation of duties

Segregation of duties prevents any single person from having too much control over critical processes. The classic example involves separating access to accounts payable from accounts receivable. Someone who can both create vendors and approve payments could potentially commit fraud.

Modern access control software should help you identify and restrict access combinations that violate segregation of duties requirements, particularly for organizations subject to regulatory compliance frameworks such as SOX, PCI DSS, or HIPAA.

Privileged access management

Privileged access represents your highest risk category. System administrators and other privileged users can access and modify virtually anything, including creating new accounts, changing security configurations, and accessing root privileges.

Best practices for managing privileged access include:

• Creating separate standard and privileged accounts for administrators
• Implementing time-bound restrictions that automatically terminate privileged sessions
• Monitoring all privileged activities
• Requiring additional approval workflows for sensitive operations

Privileged access management has evolved into its own distinct discipline within information security. Any information system containing sensitive data should have robust controls in place for privileged access.

For organizations that lack the internal resources to manage these complex requirements, SecurityScorecard MAX provides expert-managed security services that handle vendor risk assessment and continuous monitoring on your behalf.

Network and data access controls

Network access control verifies that both users and devices meet security requirements before allowing network connectivity. This includes verifying that devices have the latest security patches and are running approved anti-virus software. Your security policies should define the minimum standards devices must meet.

Data access control goes beyond simple permission assignments to govern what users can do with information. Key elements include classifying data by sensitivity, limiting access to sensitive information, restricting downloads of confidential data, and logging access to high-value assets. Controlling access to sensitive data requires constant vigilance.

Application controls

Applications represent another layer where access control features matter. Modern applications interact with databases, communicate with other services through APIs, and maintain their own permission models. Regular penetration testing can help identify weaknesses in application-level access controls.

Organizations using access control software should consider how applications interact with each other, not just how users interact with applications.

Building secure access for the future

The organizations we work with increasingly recognize that access control is a core building block of their security strategy. Getting it right requires thinking across physical and logical access, human and machine identities, and internal and external users. Learn how other companies have tackled these challenges in our customer case studies.

Where to start

We recommend starting with a clear inventory of what resources you need to protect and who needs access to each resource. Map out the access control list for your most critical systems. Identify gaps between your stated access policies and actual permissions, then systematically close those gaps through better identity and access management practices.

Zero trust security principles should guide your approach. Never assume trust based solely on network location. Verify every access request and apply the principle of least privilege consistently.

How SecurityScorecard helps you monitor access risk

Our security ratings platform enables organizations to continuously monitor their environments for greater visibility into their security posture. We provide an easy-to-read score using an A-F rating scale, giving you at-a-glance visibility into where your access controls might be falling short.

The platform helps you identify exposed administrative interfaces, weak authentication mechanisms, and other access-related vulnerabilities. Because we monitor your third-party vendors as well, you can see where access control weaknesses in your supply chain might put your organization at risk.

Threats move fast. We help you move faster.