Data Access Control

Restricted Data

Modern businesses rely on data to operate and drive growth. This data comes from external sources — from users interacting with your website or advertisements, and from third parties — as well as in-house sources like your staff, sales and support channels and other internal business processes.

How you can capture, process, and store this data is becoming increasingly regulated, and data breaches have entered the public awareness. Careless handling of data could open you to liability or irreparably damage your reputation.

Data access control refers to the tools, methodologies, and policies you implement to control who is granted access to what data. Without effective data access management, as your business grows and more people work with your data, it’s easy to make mistakes that can lead to damaging data leaks.

This article will explain data access control and the terminology surrounding it, and detail what you need to do to establish proper data access control measures in your organization.

What is data access control and what does it do?

Data access controls are the measures you take to manage access to the data that your business handles and stores.

The nature of these measures depends entirely on the tools your business uses. If you store all of your data in binders in a filing cabinet, data access control is managing who has the key to which drawer. In the case of digital data, it's the software that authenticates users and authorizes access to data based on defined policies.

Why you need data access control

Every business that collects, processes, or stores data should have a data access control policy and implementation to safeguard their data. The benefits of these data protection controls are maintaining public trust, avoiding liability for any data lost or damages caused through that loss, and securing valuable business information.

One of the primary causes of data breaches is an employee having access to data they shouldn't have access to, and either intentionally or accidentally disclosing that information to others.


Data breaches have become a newsworthy topic. The public (your current and potential future customers) are increasingly aware of the value and sensitivity of their personal information, and its usefulness to bad actors who are looking to extort, imitate, harass, or otherwise harm them using that information.

Customers will not be attracted to a service with a poor reputation for protecting their data.

Regulation and liability

If you do suffer a data breach, and are found not to have taken adequate measures to protect sensitive data, you may be found in breach of government regulation and incur hefty fines. On top of that, affected parties may seek civil penalties for any damages or losses they incur as a result of your negligence.

Companies are regularly fined for infractions of privacy regulations including the EU’s General Data Protection Regulation (GDPR), California’s Consumer Privacy Act (CPRA), and Brazil’s General Data Protection Law (LGPD) — so every day that you handle data, without the correct measures taken to control access to and protect it, puts your business at risk. Industry-specific regulations on user data, like HIPAA, can impose additional fines on top of those. It’s important to be aware of the privacy laws that cover the data you handle and to comply with them.

Protecting your vital data

Your first-party data is an asset that must be protected from accidental disclosure, dilution, deletion, modification, and corruption by inexperienced or inattentive users. First-party data is unique to your business, and is irreplaceable. It describes the internal workings of your organization, including employees, business plans, and audiences.

Online marketplaces exist where stolen and leaked information is regularly traded. If an unscrupulous competitor were to gain access to this information, they could use it to preempt your business plans, or attempt to peel away your user base using information and audience insights that you have worked hard to create.

How does data access control work?

Data access control is both an organizational and a technical process. The data you collect and the ways it is used, along with potential ways it could be exposed, must be documented. You must be aware of — and in control of — the data you collect, where it is stored, and who needs to be able to use it.

Once you know what data you have, you’ll need to define policies dictating the data that specific employees and departments require access to. Your software stack needs to be configured to limit access based on these policies. Programmatic access — such as software accessing data via an API — must also be identified so that access can be limited to only the data required for the software to function.

Once your data has been identified and policies defined, they must be implemented using the authentication and authorization mechanisms in the software you are using to access the data.

  • Authentication is the process of making sure that the person accessing a system is who they say they are. It's your username and password (and preferably two-factor authentication) combination, or an API key if you are authenticating for programmatic access.
  • Authorization checks whether an authenticated user has the rights to view or update a resource. Once you know who a user is, you can check their credentials against access policies to see what they are allowed (and not allowed) access to.

PoLP — the most important data access concept

The principle of least privilege (PoLP) dictates that you should only grant access to read and update resources to the users that require them — and nothing more.

For example, if you have a database containing customer and sales data generated from an e-commerce website, your sales team will require access to read and modify both the customer and sales data. A purchasing department requiring access to the database to make stock ordering decisions may be granted read access to the sales data only, as they have no good reason to see customer information, and no need to make alterations to the sales data.

The best way to implement PoLP is at the beginning of data access control implementation. Start by setting the default access rights to your data resources to deny all access, at any level, and then systematically work through your users, groups, and services, granting explicit access only to the resources they require.

Data access control types and definitions

The type of access control that you implement for your business will depend on your organizational structure and the policies you wish to implement, as well as the types of data access control available in the software you are using to access your data. This may factor into the decisions you make when choosing those tools.

There are a few common abbreviations that you will come across referring to different data access control types.

Discretionary access control (DAC)

Discretionary access control puts users in control of access to the resources they are responsible for. The owner of a document, data store, or other resource decides who has access. Administrators can, where required, manage access to resources, overriding the decisions made by other users.

This simple data access control method is useful in small organizations that lack centralized infrastructure and are composed of 100% trusted parties. The decision to share a resource does not require administrative oversight, streamlining the sharing of information.

However, discretionary access control becomes increasingly dangerous as more parties become involved. Administrators have less control over what data is shared as access is not granted from a central authority, and it can become easy to quickly lose track of what is being shared with whom. Users may accidentally be granted access to data they should not have access to.

For the best data security, DAC should be avoided wherever possible.

Mandatory access control (MAC)

Mandatory access control is a non-discretionary access control technique. All data access decisions and authorizations are centralized, allowing full control of who has access to what.

MAC divides users into groups or compartments, and assigns them access based on resource classification. For example, the finance department as a whole would only be granted access to resources categorized for financial use.

This access control method broadly categorizes users and data, provides a basic level of access control and data protection, and is relatively easy to manage.

However, centralized infrastructure is required to implement MAC, and there are operational overheads — somebody has to be in charge of managing the authentication and authorization system and keeping user and resource classifications up to date. The labels used to classify data must also be maintained and kept consistent. Case sensitivity, pluralization and mixed terminology can result in mis-matched labels and the wrong permissions being applied — for example users may be expected to label their sensitive documents as “confidential”, with access policies being applied based on that label, only for it to be found that some users have been mistakenly labeling theirs “privileged”, leaving the data unprotected.

Role-based access control (RBAC)

Role-based access control goes further than MAC’s group-based approach, granting non-discretionary access at an individual level.

Each user has a defined role or roles reflecting their responsibilities, and access is granted based on those roles. Users only ever have access to the resources they require access to, and nothing else. This is a more granular approach than MAC — users can be granted permission on an individual level based on their role.

RBAC is an effective implementation of PoLP. It establishes a flexible and robust authorization system that is conceptually simple, reducing the chances of accidental access being granted to sensitive resources.

Like MAC, centralized infrastructure is required to implement RBAC. Somebody has to be in charge of making sure permissions are kept up to date, as outdated permissions could hinder work by preventing access for users who require it. Overlapping roles and permission requirements can become confusing; however, you can avoid this problem by properly curating your user directory and keeping user roles and requirements up to date.

Attribute-based access control (ABAC)

Attribute-based access control or policy-based access control is commonly used when defining programmatic access to resources.

ABAC looks at the attributes or properties of both the user and the resource being accessed, to determine whether permission is granted.

ABAC allows for complex rules that give even more granular control than RBAC, but it can be challenging to manage. One of the most prominent implementations of ABAC is AWS Identity and Access Management (IAM), which grants access to files, databases, and other AWS resources based on the evaluated attributes defined in the IAM policy.

Whichever access control approach you use to secure your data, you should implement streamlined mechanisms for updating users’ permissions as their roles and access requirements change. This will discourage employees from trying to seek workarounds to expedite a task if they are kept waiting for access to the resources they need.  One method to reduce the time it takes to update permissions is by combining the above approaches, granting managers permission to assign access for data relating to their department.

What you need to do to protect your data

The first step to securing your data is to put someone in charge of protecting it. This avoids the bystander effect — people assuming that somebody else in the group is on top of a problem, when nobody is. Once responsibility is established, the following steps should be taken to improve your data security:

  • Apply PoLP (principle of least privilege). Once your data control mechanisms are in place, use them. Enact the principle of least privilege to ensure that your data is secure by default, and only grant the required access, at the required level, to the required parties.
  • Regularly review and update your data handling practices and data access control policies. Your policies will need to be updated if you change the types of data you work with. Regulations also change over time, and your policies will need to reflect those changes.
  • Regularly audit your data access control policies, mechanisms and permissions. Make sure that your data access controls actually work at a technical level — you may have restricted permissions for a resource in the GUI, but does it actually prevent that data from being accessed? Employees often change roles, or leave to work elsewhere — make sure that their access is updated or revoked as necessary. Reviewing access and maintenance logs will assist with this task and reveal any illegitimate access that may be the result of misconfigured our outdated policies.
  • Ensure that all of your data tools support data access controls, and centralize user roles and management. Data tools should allow you to manage user access and permissions, and ideally integrate with existing authentication and authorization systems. All of the tools in your digital infrastructure should be centrally managed using a solution such as LDAP or Active Directory, so that user logins and permissions are consistent across your entire network, from operating system logins to email to your data tools.
  • Track and trace your data as far as you can. Know where your data comes from, and where it is going. Ensure that all data events are logged, so that you know who viewed and updated data, when they did it, and what happened to it next.
  • Communicate. Make sure your staff know that access to the data they are working with is being monitored to discourage any mishandling. Clearly communicating data requirements will assist with implementing a robust PoLP policy, and making sure all parties are aware of the risks and repercussions if there is an accidental data disclosure will encourage careful data handling.
  • Onboard (and offboard) your employees. When a new employee arrives, follow the PoLP to determine their required access level. When an employee changes role or leaves, ensure that access is revoked. Data handling requirements and responsibilities should be communicated during employee onboarding and included in employee handbooks.

The person or persons responsible for your data policies should schedule regular check-ups and assessments to ensure that all possible measures are being taken to protect customer data.

Security information and event management (SIEM) software provides real-time monitoring and notifications about data as it moves through your infrastructure, allowing you to update user permissions if sensitive data is being incorrectly handled and respond quickly to potential data incidents.

By implementing a customer data platform (CDP) and providing a single, secure portal to access your customer data, your potential attack surface is greatly reduced. A CDP should provide the tools you need to implement your data access management plan with reduced technical overhead.

Data access control and customer data platforms

CDPs process data from multiple sources and make it available in a centralized location. This data, by its nature, will include sensitive personally identifiable information that must be handled carefully to ensure customer confidence and regulatory compliance.

When choosing a CDP, you must ensure that it has the technical features to implement data access controls appropriate for your organization. Your CDP should provide or integrate with a user authentication system and allow you to authorize access to data at a granular level. You should be able to define user roles, and update access to data based on the roles assigned (or unassigned) to users.

In addition to data access control, a CDP should ensure accountability by tracking data movement and who is accessing and updating data. This will ensure that if there is misuse, the cause can be quickly identified and mitigated. A historical record of audit logs from your CDP will prove invaluable — days, months, or even years down the track — in identifying the mishandling of confidential information.

Further reading

This article outlined the different access control methods that you can use to secure your data. For more information on customer data, and how it is managed and stored, see our other learning center articles:

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