Fine-Grained Authorization: Data Security with Precision

When we think of the term “authorization,” physical restrictions often come to mind. From office buildings to airports, “Authorized Personnel Only” signs tell us where we should and shouldn’t be.

Authorization in data ecosystems, while equally important, is rarely as straightforward – and that’s creating an easy-to-target security gap. Verizon’s 2023 Data Breach Incident Report found that stolen credentials are now the most popular entry point for breaches, occurring at more than double the rate of phishing and software vulnerability exploitation.

What is being overlooked when it comes to data access authorization, and how can you mitigate your risk exposure? In this blog, we’ll explore the key components of fine-grained authorization and how to seamlessly implement it in your data ecosystem.

What is Fine-Grained Authorization?

Fine-grained authorization refers to a general policy that controls access permissions within a system or application at a granular level. Its specificity comes from the ability to leverage various attributes, contextual parameters, and other conditions to grant or restrict access to data.

It’s important to distinguish fine-grained authorization from two similar terms: coarse-grained authorization and fine-grained access control.

Fine-Grained Authorization vs. Coarse-Grained Authorization

While fine-grained authorization takes multiple dimensions about users, context, environment, etc. into account, coarse-grained authorization builds authorization decisions around just one factor. This might be a person’s role or department within the company, security clearance level, location, or another trait.

Think of fine-grained versus coarse-grained authorization like reading a map. Knowing the exact coordinates of your intended destination will get you there, but having just the state or county means you could – and probably will – end up miles away.

Fine-Grained Authorization vs. Fine-Grained Access Control

If fine-grained authorization is the general policy regarding who can access what data, fine-grained access control is the actual enforcement mechanism. For example, attribute-based access control (ABAC) implements fine-grained permissions at query runtime using a multidimensional system, and those permissions are based on the authorization framework.

These two terms are closely related in definition and complementary in practice, but are not the same. You can learn more about the concept of fine-grained access control here.

Why Do You Need Fine-Grained Authorization?

Fine-grained authorization is foundational to protecting sensitive data at scale. By providing a nuanced structure for managing who can access what data and under which circumstances, this approach is more easily adaptable to the inevitable changes of organizations, technologies, and regulations than a coarse-grained approach.

To illustrate why fine-grained authorization is important in today’s data ecosystems, imagine an HR team composed of an entry level coordinator, a senior manager, and an auditor. The coordinator is given read-only access to data that contains personal but not confidential information, such as employee mailing addresses. The senior manager has write access to those tables, as well as information about employees’ compensation and performance. The auditor is not authorized to access the tables containing employee addresses, but is granted read-only access to compensation records for a specific time period in order to execute an audit. If any of these people changes roles, or if a new HRIS platform is introduced, a fine-grained approach to authorization would ensure that they each maintain the appropriate access permissions to do their jobs.

However, if coarse-grained authorization were used in this scenario, things could quickly break down. Each of these stakeholders could hypothetically access any HR data simply by being a member or extension of the HR department. This would expose highly sensitive employee information to people who do not have a need for it, violating the least-privilege principle which, put simply, posits that a data user should have access to the minimum amount of data needed to perform their function. Any overexposure introduces unnecessary risk of data misuse, leakage, or breach. Therefore, fine-grained authorization enables improved insider risk management, transparency, and compliance.

Key Components of Fine-Grained Authorization

As with any process, fine-grained authorization has its challenges. For instance, it must be feasible to implement in an existing data architecture without impacting performance or hindering scalability. Immuta’s 2024 State of Data Security Report found that 56% of data professionals say data security processes delay speed to access, underscoring why planning and efficiency are essential when determining an authorization strategy.

Questions to ask when defining authorization parameters include:

• If our organizational structure changes, how will our authorization structure adapt?
• Can this model easily scale with our long term goals?
• Who is responsible for managing, monitoring, and updating authorizations?

To help answer these questions and ensure that your policy is built for long term success, there are three critical components to consider.

1. Access Control Lists (ACLs)

Access control lists, known as ACLs, help define and manage permissions across a system by laying out the rules dictating who can access what data. Think of it as a guest list – if your name is on the list, you’re allowed in.

ACLs can be created for resources, individual users, and/or user groups. A resource-level ACL defines the permissions applied directly to files, folders, or other resources, while a user- or group-level ACL assigns permissions to specific users, groups, or roles. Drawing on our earlier example:

• A department-level ACL grants an HR coordinator and senior manager access to a table containing employee addresses
• A role-level ACL permits the coordinator to read the table, while the senior manager gets write access as well
• A user-level ACL gives an external auditor read access to the table for only a specific amount of time

The combination of focused ACLs facilitates the granularity needed for fine-grained authorization.

2. Attribute-Based Access Control

If ACLs are the guest list, attribute-based access control (ABAC) is the bouncer. Similar to ACLs, an ABAC policy draws on information about users, objects, and environments, but it takes the next step in actually enforcing policies based on that information.

Just as fine-grained authorization offers a more precise and nuanced approach than coarse-grained, ABAC is a more granular and dynamic access control model than RBAC (role-based access control). Since policies are enforced at query time based on multiple dimensions, data is neither overexposed nor entirely locked down.

Purpose-based access control is a subset of ABAC that considers a user’s intended action as an attribute to grant or restrict access to data. In our HR example, the auditor’s specific purpose for accessing a table could be written into a policy, ensuring they only have the data they need for the precise reason they need it. This is particularly useful for compliance with the GDPR and HIPAA, both of which require data to be used for defined and approved purposes.

Read more about role-based access control vs. attribute-based access control.

3. Identity Management & Authentication Tools

If authorization and access control are based (at least partially) on user attributes, you need a way to verify that the appropriate attributes are mapped to the right users. This is where identity management and authentication tools come into play.

At a high level, identity management involves establishing user profiles, including applications and software systems, and identifying their corresponding attributes. This may include role, department, location, and any other information that could be pertinent to access permissions.

Once these profiles are created, user identities must be authenticated in order to access organizational systems or data. Authentication methods can be based on a username and password combination, biometric information like facial recognition, or done via devices or certificates. The increasing popularity and adoption of zero trust principles, which require continuous user authentication, makes these tools even more valuable.

Platforms like Okta and Auth0, which Okta acquired in 2021, help to streamline identity management and authentication, working alongside ACLs and dynamic data access controls to translate fine-grained authorization from principle into practice.

Fine-Grained Authorization & Access Control In Action

Without a nuanced approach to data access management, you risk either opening data up too broadly or locking it down and inhibiting access altogether. This was the dilemma facing LMI, a consulting firm dedicated to powering high-functioning government agencies. All data access requests were funneled through the IT team, and all new views required copying data and re-authorizing access. With duplicate data copies and different views, analysts had difficulty coming to sound conclusions, and the data team struggled to manage access and security at scale.

Enabling a fine-grained approach to authorization and access control using Immuta eliminated the need to create copies of data, and centralizing policy enforcement provided much-needed transparency into who could access what data, when, and why. As a result, LMI accelerated time to data by more than 10x, while providing full protection for more than 1 billion government equipment maintenance records.

What’s Next?

The proliferation of AI and LLMs, regulatory requirements, and new cloud technologies are ushering in a new era of data use, as well as new risks. Organizations need to ensure that they have full visibility into what data they possess, how it’s being protected, and whether those protections are working. Meeting these needs will help stave off unauthorized access, leaks or breaches, and costly noncompliance penalties.

Fine-grained authorization is key to achieving this outcome, and leveraging a data security platform to do so streamlines many necessary steps while bolstering protection. Automated data discovery, security and access control, and data monitoring will set you up for long term success, regardless of your organization’s data goals.

To read more about fine-grained approaches to securing data, check out Data Security & Access Control 101.