Compare zero trust vs. the principle of least privilege

Zero trust and the principle of least privilege may appear to solve the same issue, but they have their differences. Read up on the two methodologies.

Security professionals are always on the lookout for new principles and frameworks to control and track application and service authentication and access within an enterprise network. Because of this, the zero-trust framework and the principle of least privilege, or POLP, are always top of mind.

While some may use the terms interchangeably, there are distinct differences between the two.

What is the principle of least privilege?

With POLP, security administrators restrict the types of applications and resources a particular user or device can access until they successfully authenticate onto a network. The concept of this is simple: Only provide access if the user or device absolutely requires it to do its job. Thus, administrators are providing the least amount of access privilege possible.

The reasoning behind principle of least privilege is that, if any one user account is compromised -- or if an employee went rogue -- least privilege significantly shrinks what networked systems a malicious actor could potentially breach. Plus, limiting the scope of access restricts wide-range lateral movement throughout the network, which can help prevent large-scale data breaches.

POLP is especially important for IT systems administrators. Prior to POLP, it was common for admins to have far greater access to systems than was required. Admins should never be allowed to log in using an account with full domain access, for example. Using POLP to restrict this access prevents a security breach from crossing over to other parts of the network.

Zero trust: Authorization and access control

The zero-trust concept takes one step back from POLP to address user/device authentication and authorization, in addition to access control. This includes the need to implement mechanisms that can accurately identify who or what is attempting to gain access and if the access behavior is odd or veers from normal activity. Authentication and authorization posture checks are performed continuously -- meaning that trust is constantly verified and reverified.

It's important to note that zero trust isn't solely about authentication and access management for end users and end devices; rather, the focus for zero trust is on data itself. The principles and methods proposed in the zero-trust model can and should extend to the data center.

In this setting, a security administrator's goal is to verify that communications between servers in a distributed workload architecture should occur. This includes continuously verifying each system, along with restricting communications of the server application to only those deemed necessary.

What are the differences between zero-trust and least-privilege access?

While they both offer similar improved security, zero trust and POLP tackle the issue via different methods.

Zero trust focuses on authorization, while least privilege focuses on user access control. Zero trust also provides a more comprehensive security methodology than POLP. A zero-trust strategy looks at who is requesting access, what they want to access and the risk if access is granted.

How to choose between zero trust and POLP

It's not a question of zero trust versus least privilege. The two technologies are similar in scope, but it doesn't need to be a one-or-the-other decision. Organizations should implement both frameworks to create a strong security methodology.

Use zero trust to handle authorization via a never trust, always verify stance and POLP to limit access privileges to only those with the proper permissions. And, with least privilege in place, even if attackers get beyond authorization, they're limited by which approved access rights they have, making it harder to move laterally within a system.

This was last published in September 2022

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