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, or Zero Trust Network Access, is a set of technologies that enables organizations to implement Zero Trust security. The term "zero trust" was coined by John Kindervag to describe a security concept in which nothing on the network is trusted by default - not end users, not devices, and not processes. This means that everything on the network must receive authentication, authorization, and continuous monitoring. Zero trust assumes risks are present both inside and outside the network at all times.

All users must receive authentication before accessing any resource within the network. Additionally, the network must validate all requests for access before it grants access.

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), ZTNA uses a variety of security technologies, including multi-factor authentication, encryption, and micro-segmentation, to secure access to resources. It often works in conjunction with other comprehensive security plans, like Secure Access Service Edge (SASE), to completely protect a 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.

ZTNA 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?

The way ZTNA operates is simple: it denies everything access to resources unless explicitly allowed. It differs from network-centric solutions, using SDP principles.

At the core of ZTNA is the concept of microsegmentation. Microsegmentation refers to the process of creating granular security zones around specific resources, applications, or workloads. The network achieves this through the use of software-defined networking (SDN) technologies.

To establish a ZTNA connection, a user typically needs to authenticate themselves through a combination of traditional authentication methods. Once the user is authenticated, ZTNA uses a dynamic policy engine to determine the user's level of authorization for the requested resource. The engine takes into account various factors, like the user's role, the sensitivity of data or application, and the security posture of the user's device.

Once the system approves a user, then ZTNA establishes a secure, encrypted connection between the user and the resource using network segmentation. The goal is to ensure that the user can only access the specific resource that they're authorized to access and nothing more.

ZTNA is useful in organizations as it allows them to enforce security policies on a per-resource basis rather than a network-wide one. That way, an organization gains greater control over their data and applications, even if they host in a cloud environment.

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. ZTNA 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 sequence of steps a user takes to access a protected resource using ZTNA. Here are the typical steps involved:

1. User authentication. The user initiates the access request by providing their credentials for authentication through a web portal or client software.
2. Authorization. Once the user is authenticated, ZTNA checks access privilege to ensure they have the authority to access the resources.
3. Policy enforcement. It enforces security policies to ensure that the user accesses the resource securely.
4. Secure connection. ZTNA establishes a secure connection between the user's device and the requested resource using Transport Layer Security (TLS) or tunneling procedures.
5. Resource access. Once the secure connection is established, the user is granted access to the requested resource. This can include applications, data, or other network resources.
6. Continuous monitoring. ZTNA continuously monitors a user's behavior and the network traffic in order to mitigate security threats. If any suspicious activity is detected, ZTNA can take proactive measures to mitigate the threat.

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 involves deploying specialized software agents on devices that require access to network resources. With agent-based ZTNA, each device is assigned a software agent that serves as a unique identifier for that device. These agents are responsible for authenticating and authorizing access requests based on policies set by administrators.

When a user or device attempts to access a network resource, the agent on that device initiates an authentication process. This validates the user's credentials and verifies that the device has authorization to access the resource. The agent then applies the appropriate policies to determine whether the user should receive access.

Agent-based ZTNA enables granular access control, allowing administrators to set policies and dictate what resources users can access. Additionally, because each device has its own agent, it's easier to enforce security policies across a large number of devices.

Service-based ZTNA

Service-based ZTNA relies on a cloud service instead of an endpoint application. It does not require use or installation of an agent. The approach grants access to applications and resources based on the identity of the user, device, and environment rather than simply relying on the network perimeter.

With service-based Zero Trust Network Access, a cloud-based service defines access policies. It acts as an intermediary between users and the resources they need to access. The service in the cloud verifies that the user's device and network environment meet the security requirements before granting access to the requested resources.

It provides several benefits over traditional network-based security models; it enables secure access to resources and reduces the attack surface by limiting access to only those resources necessary for a user's job.

What's the difference between ZTNA and VPN?

Though VPNs, or virtual private networks, tend to be the standard choice for organizations looking to protect their resources from unauthorized remote access, they have limitations. They're perimeter-focused, controlled at the network level, and have poor support for certain devices. In many ways, when comparing ZTNA vs VPN, ZTNA becomes the better option.

ZTNA has some advantages over traditional VPNs. For one, ZTNA and microsegmentation mean that resources break down into smaller segments, making it harder for attackers to move across a network.

They provide greater access control than a VPN and are more scalable, as VPNs can become overwhelmed as more users connect. They also tend to be more user-friendly in certain ways. VPNs allow users access to resources from anywhere on any device.

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 framework that assumes all users, devices, and applications are potential threats. Therefore, they should not be trusted by default. Instead, it requires continuous verification of users' identities and devices and limits access to resources based on contextual information. The architecture reduces the attack surface and minimize the impact of potential security breaches.

How does ZTNA differ from ZTAA?

ZTAA stands for Zero Trust Application Access. ZTAA differs from ZTNA in that the former is a subset of the latter. It focuses specifically on application access, whereas Zero Trust Network Access is a more comprehensive model that includes all network resources.