What is Zero Trust Architecture?

Zero Trust Architecture (ZTA) may seem like a relatively new security model, but it dates back to 2011, when John Kindervag, former Forrester analyst, authored the original trilogy of Zero Trust papers. ZTA is not a product but a security strategy based on eliminating implicit trust and continuously authorizing at every stage of digital interaction. Zero Trust is designed to protect modern environments and enable digital transformation by leveraging network segmentation, using strong authentication methods, providing Layer 7 threat prevention, preventing lateral movement, and “least privilege” or “least access” policies. The Zero-Trust Security model has been gaining popularity in recent years as organizations become more aware of the risk of traditional security models.

This article outlines what Zero Trust is, how Zero Trust works, the five core principles of Zero Trust, and the stages of implementing Zero-Trust security.

What is Zero Trust Architecture?

Zero Trust Architecture (ZTA) is a security model based on the principle of least privilege. Least privilege means that users and devices are only granted the permissions they need to perform their tasks. This helps reduce the attack surface and makes it more difficult for attackers to gain access to sensitive data.

Zero Trust assumes that no user or device can be trusted, even if they are inside the corporate network. This is in contrast to traditional security models, which typically trust users and devices inside the network and only require authentication for users outside the network.

How Zero Trust Works

Zero Trust works by implementing a number of security controls that are designed to verify the identity of users and devices before granting them access to resources, such as:

• Authentication - Authentication is performed every time a user or device attempts to access a resource. This helps to ensure that only authorized users have access to the resources they need.
• Authorization - Once a user or device is authenticated, they are only granted the permissions they need to perform their tasks. This helps to reduce the attack surface and makes it more difficult for attackers to gain access to sensitive data.
• Continuous monitoring - All network traffic and activity is continuously monitored for suspicious behavior. This helps to detect and respond to attacks quickly.
• Micro-segmentation - This involves dividing the network into smaller segments, each with its own security policies. This makes it more difficult for attackers to move laterally within the network if they are able to breach one segment.
• Identity access management (IAM) - Implementing strong IAM controls ensures that only authorized users have access to the resources they need.

A comprehensive Zero Trust approach encompasses users, applications, and infrastructure. Zero Trust requires strong authentication of user identity, application of “least privilege” policies, and verification of user integrity. Apply Zero Trust to applications removes implicit trust with various components of applications when they talk to each other. A fundamental concept of Zero Trust is that no user, device, network flow, or application can be fully trusted. Therefore, continuous monitoring at runtime is necessary to validate any behavior. Everything infrastructure related - routers, switches, cloud, IoT, and supply chain - must be addressed with a Zero Trust approach in mind.

By implementing these security controls, Zero Trust Architecture can help prevent attackers from gaining access to sensitive data even if they are able to breach the network perimeter.

Zero Trust Use Cases

Zero Trust is a versatile security model that can be used to protect a variety of assets and resources, including:

Data

Zero Trust can be used to protect sensitive data, such as financial information, customer data, and intellectual property.

Applications

Zero Trust can be used to protect applications, such as web applications, databases, and cloud applications.

Networks

Zero Trust can be used to protect networks, such as a corporate network, the cloud network, and the Internet of Things (IoT) network.

Remote access

Zero Trust can be used to secure remote access to applications and resources. This is done by implementing strong authentication and authorization controls, and monitoring for suspicious behavior.

Malicious insider threats

Zero Trust can be used to protect against malicious insider threats. This is done by implementing least privilege and continuous monitoring to ensure that users only have access to the resources they need and by detecting suspicious behavior.

Secure access to the cloud

Zero Trust can be used to secure access to cloud-based applications and resources. This is done by implementing IAM controls to ensure that only authorized users have access to cloud resources and by monitoring for suspicious behavior.

Securing hybrid and multi-cloud environments

Zero Trust can be used to secure hybrid and multi-cloud environments. This is done by implementing IAM controls to ensure that only authorized users have access to cloud resources and by monitoring for suspicious behavior across all cloud environments.

5 Core Principles of Zero Trust Security

There are five core principles of Zero Trust security, and by implementing them, organizations can help to reduce their risk of being compromised and protect their sensitive data.

1. Identity - To ensure properly controlled privileged data access, organizations must employ risk-based access by taking a holistic view of users and gaining a deep understanding of their responsibilities and authorities, as well as having the ability to verify user identities when they attempt to access data. They must also implement strong authentication practices and consolidate the means of authentication to as few identity authentication systems as practicable.
2. Devices - A Zero Trust security strategy includes treating all devices connected to the network as untrusted and a potential threat. Implementing zero trust security requires the ability to determine if a device is a threat and isolating those that are compromised.
3. Networks - A Zero Trust network is micro-segmented, where perimeters are defined around each of the organization’s valuable assets. At these boundaries, it is possible to perform security inspection and enforce access controls, which makes it easier to block the lateral movement of threats through the network and to contain and isolate a potential breach.
4. Applications and Workloads - Organizations must treat all applications as internet-connected, routinely subject their applications to rigorous testing, and welcome external vulnerability reports.
5. Data - Implementing zero trust requires identifying caches of sensitive or valuable data, mapping common data flaws, and defining access requirements based on business needs. These policies must also be consistently defined and enforced across an organization’s entire IT ecosystem, including workstations, mobile devices, application and database servers, and cloud deployments.

Stages of Implementing Zero Trust Maturity Model

Implementing zero trust can be a complex and challenging process, but it’s an important step in protecting your organization from cyberattacks. The stages can vary depending on an organization’s specific needs and requirements, but these are some general steps that most organizations need to follow:

Stage 1: Assess the current security posture

Stage 1 involves identifying the organization’s assets, understanding the current security controls, and assessing the risk of cyber attacks. The assessment should also identify the organization’s goals for implementing Zero Trust.

Stage 2: Develop a Zero Trust Maturity strategy

Stage 2 involves defining the organization’s security goals, identifying the security controls needed to achieve those goals, and developing a plan for implementing these controls. The strategy should include a timeline for implementing Zero Trust and a plan for monitoring and maintaining the Zero Trust environment.

Stage 3: Implement Zero Trust controls

Stage 3 involved deploying the necessary technology, configuring the security controls, and training users on the new security policies. The implementation process should be phased in gradually so that the organization can test and validate the new security controls before deploying them to all users.

Stage 4: Monitor and maintain the Zero Trust environment

Stage 4 involves continuously monitoring the security environment for threats, responding to incidents, and making changes to the security controls as needed. The monitoring process should include both automated and manual monitoring so that the organization can detect and respond to threats quickly.

Stage 5: Continuously improve

Stage 5 involves reviewing the security posture regularly, identifying new threats, and making changes to the security controls as needed. The improvement process should be an ongoing process so that the organization can stay ahead of the evolving threat landscape.

The Zero Trust Maturity Model is designed to protect organizations from cyberattacks, but the journey towards Zero Trust is long and rarely aligned with the traditional cybersecurity strategies to which we have grown accustomed. It is important to remember Zero Trust is a journey, not a destination. It is an ongoing process of improvement and adaptation. Zero Trust security solutions are not a silver bullet. It is one part of a comprehensive security strategy. Lastly, Zero Trust is not easy. It requires a substantial investment of time, money, and resources.

However, the benefits of Zero Trust Maturity are significant. By implementing Zero trust, organizations can protect themselves from a wide range of cyberattacks, including those that exploit traditional security perimeters.

Learn more about implementing Zero Trust in your organization by taking SEC530 Defensible Security Architecture and Engineering: Implementing Zero Trust for the Hybrid Enterprise.