What Is Zero Trust Network Access (ZTNA)?

In today's digital landscape, traditional security measures are no longer enough to protect against evolving threats. But there are new solutions - like ZTNA (Zero Trust Network Access). ZTNA is a security model that provides secure access to applications, services, and data. In this article, learn what ZTNA is, how it works, and its benefits as a protocol.

What is ZTNA?

ZTNA (Zero Trust Network Access) is a group of tools that help enforce a "Zero Trust" security model. The idea of Zero Trust, created by John Kindervag, means no user, device, or program is trusted by default—not even those inside the network.

Instead, every user and request must be checked and approved before they can access anything. The network assumes there are always risks, so it requires constant verification to keep everything secure.

ZTNA focuses on securing individual access requests based on user and device identity, location, and other contextual factors. This approach helps to prevent unauthorized access to sensitive data, even if a hacker manages to breach the network perimeter.

Like software-defined perimeter (SDP), it uses tools like multi-factor authentication, encryption, and micro-segmentation to keep access secure. It often works with other security systems, like Secure Access Service Edge (SASE), to fully protect the network.

What does ZTNA do?

ZTNA specifically does the following:

• Maps all systems, apps, and remote work that users may need to access from a separate location.
• Verifies the identities of all parties to ensure only authorized users have access to resources.
• Enforces access policies that specify what resources each user can access.
• Uses encryption to protect data in transit or at rest between the user's device and the resource accessed.
• Divides the network into smaller segments to limit the attack surface.
• Checks the user's device for compliance with security policies, such as antivirus protection and up-to-date software.
• Monitors the user's activity to detect anomalies.
• Treats policy as dynamic in real time.
• Verifies that endpoints are still secure.
• Works in conjunction with other security technologies, such as firewalls, to provide a comprehensive security solution.

Contrary to popular belief, Trust Zero principles aim to eliminate the concept of trust altogether rather than making the system secure. Trust is granted conditionally, but it must be continually evaluated.

Zero Trust leverages machine learning and behavior analytics to detect suspicious activity in real time. This helps the system take action before they can cause any damage.

How does ZTNA work?

ZTNA works by blocking access to everything unless access is specifically allowed. Unlike older, network-based security tools, ZTNA uses software-defined perimeter (SDP) ideas to protect resources.

A key part of ZTNA is microsegmentation, which means creating small, separate zones around apps, data, or systems. This is done using software-defined networking (SDN).

To connect through Zero Trust, users must first prove who they are using standard login methods. Once verified, a policy engine checks whether the user should be allowed to access a certain resource. It looks at things like the user’s role, the sensitivity of the data, and how secure the user’s device is.

If approved, ZTNA sets up a secure, encrypted connection that gives the user access only to that one specific resource—nothing else.

ZTNA is helpful because it enforces security one resource at a time, not across the whole network. This gives companies more control over who can see what, even in the cloud.

Benefits of Zero Trust Network Access

ZTNA offers several benefits to organizations looking to improve their security. Some of the benefits of adopting ZTNA include:

• Enabling micro-segmentation of the network. The network divides into smaller segments with access to each segment restricted based on the user's role, device, and experience. This approach then makes it harder for attackers to move within a network, limiting potential breaches.
• Mitigation of cyber threats. Insider threats are a serious threat to businesses. ZTNA helps reduce the risk by ensuring that only authorized users can access specific resources.
• The ability to make applications invisible on the Internet. Zero Trust Network Access creates a virtual darknet by masking the IP address of the application. Hiding the IP also reduces the risk of external attacks.
• Prevention of malware. With ZTNA, all access to resources is authenticated, authorized, and encrypted, which reduces the risk of malware.
• Better network visibility. ZTNA produces more granular control over network access, avoiding blind spots and improving visibility of network traffic. This also allows entities to identify potential threats.
• An enhanced user experience. ZTNA allows users to access resources from any location anywhere without compromised security.
• Simplified management. The security protocol provides a centralized policy engine that can enforce security policies across multiple applications and resources. This, therefore, streamlines security management.

ZTNA user flow

The ZTNA user flow is the set of steps a user follows to reach a protected resource. Here’s how it usually works:

1. Authentication. The user starts by logging in through a web portal or app with their credentials.
2. Authorization. After confirming identity, ZTNA checks if the user is allowed to access the requested resource.
3. Policy enforcement. Security policies are applied to make sure the connection follows all rules.
4. Secure connection. A safe link is set up using Transport Layer Security or tunneling to protect the data.
5. Access granted. The user is allowed to reach apps, files, or services they’re approved to use.
6. Ongoing monitoring. ZTNA keeps watching for unusual behavior. If a threat is detected, it can block access or alert security teams.

Types of ZTNA

Many see ZTNA solutions as the potential future of network security. It is, in fact, a necessity for today's hybrid organizations. After selecting a ZTNA product, organizations use one of two primary approaches: agent-based ZTNA and service-based ZTNA.

Agent-based ZTNA

Agent-based ZTNA uses special software installed on each device that needs access to the network. This software, called an agent, acts as a unique ID for the device.

When someone tries to access a resource, the agent checks their login info and confirms that the device is allowed. It also checks the rules set by the company to decide if access should be granted.

With agent-based Zero Trust Network Access, companies can control exactly what users and devices can access. Since each device has its own agent, it’s easier to manage security across many devices.

Service-based ZTNA

Service-based ZTNA uses the cloud instead of installing software on each device. It doesn’t need any special app or agent to work. Instead, it checks who the user is, what device they’re using, and where they’re logging in from.

A cloud service controls access rules and sits between the user and the resource. It makes sure the device and network meet security standards before allowing access.

This method improves security by only giving users access to the resources they need, making it harder for attackers to reach sensitive data.

What's the difference between ZTNA and VPN?

VPNs (virtual private networks) are a common way for organizations to give remote users secure access. But they have limits. VPNs focus on the network’s perimeter, don’t work well with all devices, and can be hard to manage. When comparing ZTNA to VPN, ZTNA often comes out ahead.

Zero Trust Network Access offers better protection by breaking the network into smaller parts using microsegmentation. This makes it harder for attackers to move around. It also gives better access control, works well as more users connect, and can be easier to use. Unlike VPNs, which give access to the whole network, ZTNA only allows access to what the user needs.

Frequently asked questions

What is ZTNA 2.0?

ZTNA 2.0 improves upon the original ZTNA used by Palo Alto Networks. Though it doesn't drastically change the protocol, it offers an updated and more secure version.

What are the three main concepts of Zero Trust?

The three main concepts of Zero Trust are continuous access verification, least privileged access, and risk awareness.

What is a Zero Trust architecture?

Zero Trust architecture is a security model that treats every user, device, and app as a possible threat. Nothing is trusted by default. Instead, users and devices must be verified again and again.

Access to data or tools is only given based on specific rules and context, like who the user is or where they’re logging in from. This setup lowers the risk of attacks and limits damage if a breach happens.

How does ZTNA differ from ZTAA?

ZTAA stands for Zero Trust Application Access. It’s a part of the larger Zero Trust Network Access (ZTNA) model.

ZTAA focuses only on giving secure access to specific apps. Zero Trust Network Access, on the other hand, covers access to all network resources, not just apps.

In short, ZTAA is a smaller, more focused piece of the bigger Zero Trust puzzle.