Zero trust vs least privilege

In the context of the Zero Trust vs. least privilege debate, this post explores the difference between Zero Trust and least privilege, how the Zero Trust security model and least privilege access control work together, and where each fits in a modern security program.

Organizations need both Zero Trust and least privilege. These two fundamental security approaches verify all requests and restrict all permissions. 

This article explains the operation of each security method as well as their distinct approaches to defense. It also provides guidance on their combined use for enhanced security.

Security operations previously focused on creating an unbreakable defensive boundary. 

The rule was: Trust the people and devices inside the network. Be suspicious of everything on the outside. 

This "castle-and-moat" security model proved effective when technology systems were run from restricted server rooms. 

But cloud computing, SaaS solutions, and hybrid work environments have resulted in traditional system perimeters dissolving. Cloud, SaaS, and remote endpoints now make up a fragmented and complex “frontline,” with inconsistent controls that create gaps attackers can exploit. 

Malicious actors know that if they find one unlocked door—usually a stolen password—they can often wander freely through the entire network. This is precisely what the Zero Trust security model was designed to prevent.

The Zero Trust security model follows a single core belief surrounding verification. 

The new rule is: All users and systems must require verification before being granted access. 

Under this model, there is no free pass. Every single time someone or something tries to access a resource, they must authenticate their identity and prove they have access rights to the resources they seek.

Making a Zero Trust architecture work requires a few key components:

• Policy decision point (PDP): The PDP operates as the central regulatory system of the entire network. It's where you define and store all the rules about who has access to what.

• Policy enforcement point (PEP): This is your security guard. The system functions as a security checkpoint that protects all resources while implementing the policies defined by the PDP.

Trust algorithm: This evaluates various real-time indicators (e.g., user identity, device health status, location data, and data sensitivity) to generate a trust score for each request.

Implementing Zero Trust requires organizations to establish ongoing verification processes for all identity and device access, as well as network, workload, and data security:

• Devices: Companies must verify the security posture of all laptops and phones through software updates and security tool verification. The testing process identifies non-compliant devices, which are placed in a digital waiting area until they achieve safety standards.

• Networks: Micro-segmentation is the main player here. By dividing your network into tiny, isolated zones, you prevent an intruder from moving around freely. All traffic between servers (east-west) needs to be encrypted and pass through a PEP checkpoint.

• Applications & workloads: Applications, together with services, require robust identity systems. This can be done using methods like mTLS to ensure services are securely talking to each other, and by enforcing strict authorization checks at the front door (gateways) of every application.

• Data: Are you fully aware of what your data consists of and its level of sensitivity? The process of classification and labeling enables organizations to develop smart policies that implement least privilege access controls, preventing sensitive information from leaving the organization.

Following the least privilege principle, least privilege access control requires that all users and non-human identities receive permissions that exactly match their required tasks and only remain active during the time needed to complete those tasks. 

Limiting permissions to specific times and tasks: 

• Minimizes system vulnerabilities 

• Restricts damage from compromised credentials

• Prevents unauthorized system access 

• Makes audit processes easier and regulatory requirements more achievable

• Provides clear visibility into all access elevation activities

Teams use three main operational controls to implement least privilege in their daily operations: 

• RBAC/ABAC function together to restrict resource access based on job titles and user characteristics; RBAC handles basic access control, while ABAC offers detailed context-based authorization checks.

• Just-in-time (JIT) allows a user to ask for special permissions for a short period to perform a specific task, with any rights granted terminated when the work is complete.

• Time-boxed tokens grant access credentials with an expiration date, so even if a token is stolen, exposure is short‑lived and any impact contained.

The implementation of least privilege access control requires a methodical approach to provide each identity with the smallest set of permissions needed to perform its duties for a limited duration. 

These are the essential steps for successful implementation:

1. Inventory and map privileges: You cannot protect what you do not even know is yours. This step demands complete identification of human and machine identities to establish their current permissions and necessary access permissions.

2. Shrink service account scopes: After creating a map, you can begin to limit the permissions of accounts that have excessive access. 

3. Credential rotation and exceptions: Organizations need to adopt credential rotation and temporary identity systems for automated operations while also making just-in-time access their default security approach.

The discussion of Zero Trust vs. least privilege comes down to the two concepts dealing with different security issues. 

The table below presents a clear comparison.

Zero Trust and least privilege security solutions deliver a major security improvement when deployed together, despite their distinct implementation methods. 

Their combination significantly reduces the potential damage from a breach, makes it much harder for attackers to move around, and delivers a crystal-clear record of who is accessing what and why.

If you’re evaluating platforms to operationalize these practices, AlgoSec can help by:

• Modeling application connectivity

• Orchestrating network security policy changes

• Supporting micro-segmentation

• Maintaining continuous compliance across hybrid and multi‑cloud environments

All these capabilities reinforce both Zero Trust and least privilege. 

Explore AlgoSec Cloud Enterprise for multi‑cloud and hybrid policy automation, see how our approach helps application owners model and secure application connectivity, and learn about our native integrations with AWS.

Schedule a demo of AlgoSec today.