Zero Trust Architecture: Transforming Cybersecurity for Perimeter-less Networks in the Digital Age

What Is Zero Trust Architecture?

Zero trust architecture is a security architecture built to reduce a network's attack surface, prevent lateral movement of threats, and lower the risk of a data breach based on the zero trust security model. Such a model puts aside the traditional "network perimeter"—inside of which all devices and users are trusted and given broad permissions—in favor of least-privileged access controls, granular micro segmentation, and multifactor authentication (MFA).

Understanding the Need for Zero Trust Architecture

For decades, organizations built and reconfigured complex, wide-area hub-and-spoke networks. In these environments, users and branches connect to the data center by way of private connections. To access applications they need, the users have to be on the network. Hub-and-spoke networks are secured with stacks of appliances such as VPNs and “next-generation” firewalls, using an architecture known as castle-and-moat network security.

This approach served organizations well when their applications resided in their data centers, but now—amid the growing popularity of cloud services and rising data security concerns—it’s slowing them down.

Today, digital transformation is accelerating as organizations embrace the cloud, mobility, AI, the internet of things (IoT), and operational technology (OT) to become more agile and competitive. Users are everywhere, and organizations’ data no longer sits exclusively in their data centers. To collaborate and stay productive, users want direct access to apps from anywhere, at any time.

What Are the Core Principles of Zero Trust?

Zero trust is more than the sum of user identity, segmentation, and secure access. It's a security strategy upon which to build a complete security ecosystem. At its core are three tenets:

1. Terminate every connection:?Unlike the passthrough inspection techniques common to legacy technologies (e.g., firewalls), an effective zero trust architecture terminates every connection to allow an inline proxy architecture to inspect all traffic, including encrypted traffic, in real time—before it reaches its destination.
2. Protect data using granular context-based policies:?Zero trust policies verify access requests and rights based on context, including user identity, device, location, type of content, and the application being requested. Policies are adaptive, so validation and user access privileges are continually reassessed as context changes.
3. Reduce risk by eliminating the attack surface:?With a zero trust approach, users connect directly to apps and resources, never to networks (see?ZTNA). Direct connections eliminate the risk of lateral movement and prevent compromised devices from infecting other resources. Plus, users and apps are invisible to the internet, so they can’t be discovered or?attacked.

What Are the 5 Pillars of Zero Trust Architecture?

The five “pillars” of zero trust were first laid out by the US Cybersecurity and Infrastructure Security Agency (CISA) to guide the key zero trust capabilities government agencies (and other organizations) should pursue as in their zero trust strategies. The five pillars are:

• Identity—moving to a least-privileged access approach to identity management.
• Devices—ensuring the integrity of the devices used access services and?data.
• Networks—aligning network segmentation and protections according to the needs of their application workflows instead of the implicit trust inherent in traditional network segmentation.
• Applications and workloads—integrating protections more closely with application workflows, giving access to applications based on identity, device compliance, and other attributes.
• Data—shifting to a data-centric approach to cybersecurity, starting with identifying, categorizing, and inventorying data assets.

How Does Zero Trust Architecture Work?

Based on a simple ideal—never trust, always verify—zero trust begins with the assumption that everything on the network is hostile or compromised, and access is only granted after user identity, device posture, and business context have been verified and policy checks enforced. All traffic must be logged and inspected, requiring a degree of visibility traditional security controls can’t achieve.

A true zero trust approach is best implemented with a proxy-based architecture that connects users directly to applications instead of the network, enabling further controls to be applied before connections are permitted or blocked.

Before establishing a connection, a zero trust architecture subjects every connection to a three-step process:

1. Verify identity and context.?Once the user/device, workload, or IoT/OT device requests a connection, irrespective of the underlying network, the zero trust architecture first terminates the connection and verifies identity and context by understanding the “who, what, and where” of the request.
2. Control risk.?Once the identity and context of the requesting entity are verified and segmentation rules are applied, the zero trust architecture evaluates the risk associated with the connection request and inspects the traffic for cyberthreats and sensitive data.
3. Enforce policy.?Finally, a risk score is computed for the user, workload, or device to determine whether it’s allowed or restricted. If the entity is allowed, the zero trust architecture establishes a secure connection to the internet, SaaS app, or IaaS/PaaS environment.

Benefits of Zero Trust Architecture

A zero trust architecture provides the precise, contextual user access you need to run at the speed of modern business while protecting your users and data from malware and other cyberattacks. As the bedrock of ZTNA, an effective zero trust architecture helps you:

• Grant safe, fast access?to data and applications for remote workers, including employees and partners, wherever they are, improving the user experience
• Provide reliable remote access?as well as manage and enforce security policy more easily and consistently than you can with legacy technology like VPNs
• Protect sensitive data and apps—on-premises or in a cloud environment, in transit or at rest—with tight security controls, including encryption, authentication, health checks, and more
• Stop insider threats?by no longer granting default, implicit trust to any user or device inside your network perimeter
• Restrict lateral movement?with granular access policies down to the resource level, reducing the likelihood of a breach
• Detect, respond to, and recover?from successful breaches more quickly and effectively to mitigate their impact
• Gain deeper visibility?into the what, when, how, and where of users’ and entities’ activities with detailed monitoring and logging of sessions and actions taken
• Assess your risk in real time?with detailed authentication logs, device and resource health checks, user and entity behavior analytics, and more.

How Does Zero Trust Architecture Outperform Traditional Security Models?

Zero trust architecture surpasses traditional security models because of its proactive, adaptive, and data-centric approach. Traditional models rely on perimeter defenses, while zero trust acknowledges that threats can come from inside the network as well as outside, and continuously validates the identity and security posture of users and devices.

?By enforcing granular least-privileged access controls, zero trust grants users and devices only the minimum access necessary. Continuous monitoring, MFA, and behavioral analytics detect threats in real time, before they can become successful attacks. Its adaptability makes zero trust more agile, in turn making it better suited than traditional models to secure the massive attack surfaces and novel vulnerabilities inherent to today’s remote work and cloud-driven world.