Information Center

Zero Trust Security: The Comprehensive Guide

Today, data breaches are common, and businesses are always on the verge of severely compromising sensitive information, so cybersecurity best practices are necessary now more than ever. For years, enterprises have modeled their cybersecurity around a virtual perimeter of trust that includes trusted network infrastructure, users, and devices.

Unfortunately, cybercriminals and malicious actors have exploited this cybersecurity model for years. Undoubtedly, there is an immediate need for robust cybersecurity systems that don’t leave loopholes (think of numerous devices, digital touchpoints, and users), providing a risk-free ecosystem. Here is where a zero trust model comes into play.

So how can you turn the zero trust security concept into a reality for your business or organization? This definitive guide explains what zero trust means and how it works.

Table of Contents:

  1. What does zero trust mean?

  2. What is a zero trust network?

  3. How does zero trust work?

  4. Principles of zero trust security

  5. What is zero trust architecture?

  6. Zero trust technology

  7. Why is zero trust important?

  8. How to implement zero trust security?

  9. Benefits of zero trust security

  10. Challenges of zero trust security

  11. The bottom line


What Does Zero Trust Mean?

Zero trust refers to a security philosophy stemming from the concept of “trust nothing, verify everything.” The cybersecurity approach ensures organizations grant access to only confirmed authorized and safe users, systems, networks, and processes. As a result, it prevents bad actors from gaining access and doing damage. Businesses can also defend against ever-emerging threats like ransomware.

What is a Zero Trust Network?

Zero trust is a relatively new IT security model requiring strict identity verification for every device or user trying to access a private network’s resources, regardless of whether they sit within or outside the network perimeter.

Although the primary technology associated with the zero trust model is Zero Trust Network Access (ZTNA), the framework is a holistic approach to network security, incorporating several different technologies and principles.

Simply put, traditional IT network security trusts users and devices inside the network, while the zero trust architecture trusts nothing and no one.

The traditional IT network security relied on the castle-and-moat concept where it was hard to gain access from outside while the network trusted everyone inside by default. However, problems arose when malicious actors gained access and enjoyed free rein over everything inside the network.

At its core, the zero trust security model relates to a paradigm shift in how businesses and organizations conceive their networks, systems, and IT infrastructure. Under the previous model, all the servers, computers, and other devices existed in the same network and trusted each other.

IT teams had to set up security tools like antivirus and firewalls, which viewed anything outside the virtual perimeter as bad and everything inside as good, warranting no additional scrutiny. However, the explosion of mobile devices, remote work, and cloud services has radically challenged those assumptions. Today, organizations no longer keep their data in one place. Instead, it’s spread across servers and cloud vendors, making it challenging to have primary security control for the entire network.

Today’s organizations cannot physically control every device their employees use anymore. Additionally, even if they could control every device within their networks, the old model was never secure. Once an attacker bypassed the perimeter defenses remotely or physically by infiltrating the organization, the network granted them access, trust, and freedom.

How Does Zero Trust Work?

Zero trust is a concept and a going concern, not a one-off action. For example, instead of trusting particular connections, users, and devices from certain places (such as employees of an organization), zero trust demands users prove they should gain access.

Typically, gaining access to the network means logging into a corporate account using usernames and passwords plus biometrics or hardware security keys, making it harder for malicious actors to impersonate users.

What’s more, the system is configured on a need-to-access or need-to-know basis even after getting through. So, for example, it means that if invoicing a contractor is not part of your job, your corporate account shouldn’t have access to the billing platform. Thus, a zero trust network:

  • Limits and controls access to private networks
  • Logs and inspects all network traffic
  • Verifies and secures network resources

What this means is that the zero trust model ensures data and network resources remain inaccessible by default. Consequently, users can only access them under the right circumstances and on a limited-time basis; this is known as least-privilege access.

The security model verifies and authorizes all connections, such as when users connect to applications or software to data sets using an application programming interface (API). In addition, it ensures all interactions meet the organization’s security policies’ conditional requirements.

Additionally, a zero trust security strategy authenticates and authorizes devices, network flows, and connections based on dynamic policies. It uses context from numerous data sources.

Zero trust requires a portfolio of security capabilities and experiences, including:

  • Identity: Defines and governs zero trust security policies and manages access across users and privileged accounts using multi-factor authentication, SSO, and lifecycle management
  • Data: Protects critical data using proven zero trust best practices; discovers, classifies, and manages data access according to risk
  • Analytics and Visibility: Monitors and enforces zero trust policies with intelligent analytics; allows organizations to view and monitor user behavior, resources, and data connections
  • Devices and Workloads: Defends the organization using zero trust practices – from secured apps to monitoring and managing endpoints
  • Network and Endpoint: Applies modern solutions and proven skills and expertise to protect network infrastructures and endpoints
  • Automation and Orchestration: Rapidly solves and iterates security issues as part of zero trust practice using orchestrated actions and typical playbooks

Principles of Zero Trust Security

Zero trust relies on the following core principles to secure and protect the enterprise IT environment:

1. Continuous Monitoring and Validation

The zero trust model assumes the presence of attackers both within and outside the network. Therefore, it does not grant anyone or anything automatic trust and access. Instead, it verifies every user’s identity and privileges, plus device identity and security. Moreover, organizations can set connections and logins to timeout periodically once established, which forces continuous re-verification of users and devices.

2. Principle of Least Privilege

The least privilege access means giving users access on a need-to-access and need-to-know basis. As a result, it minimizes each user’s exposure to a network’s sensitive parts.

Implementing least privilege requires the careful management of user permissions. Additionally, VPNs are not suitable for least privilege approaches to authorization because they give users access to the entire connected network.

3. Micro-Segmentation

It’s the practice of breaking up a network’s security perimeters into smaller zones, ensuring separate access for separate areas. For example, a network that stores files in a single data center could microsegment them into dozens of distinct, secure zones. Therefore, a user or program requires separate authorization for the different file zones.

4. Device Access Control

Zero trust also requires strict device access controls. These should monitor how different devices try to access their network, ensure they are authorized, and assess them to determine if attackers have compromised them.

5. Preventing Lateral Movement

Lateral movement in network security refers to the ability of an attacker to move within the network after gaining access. Attackers can compromise other network parts as they move through them, making it difficult to detect them. Network segmentation prevents lateral movement and allows the IT team to detect and quarantine the compromised user account or device.

6. Multi-Factor Authentication (MFA)

It requires more than a single piece of user-authenticating evidence, meaning just entering a username and password is not enough to gain access. For example, the 2-factor authorization (2FA) is a common application of MFA used on platforms such as Google and Facebook. 2FA requires users to enter a password plus a passcode sent to a secondary device.

What is Zero Trust Architecture?

Zero trust architecture (ZTA) refers to an enterprise cybersecurity infrastructure based on zero trust components and principles designed to prevent data and network breaches while limiting internal lateral movement. ZTA strengthens an organization’s cybersecurity, keeps unauthorized users out of its private network, and protects its assets from threats.

Essentially, ZTA allows network users to only access what they require to perform their jobs. It also identifies potentially malicious or anomalous activities and allows the quarantining of affected segments to prevent the spread of cyberattacks across the network.

Zero trust security assumes users or devices have compromised the network and challenges them to prove they are not attackers.

The National Institute of Standards and Technology (NIST) already established principles of zero trust architecture for government agencies. These NIST principles are also applicable for private organizations and include the following:

  • Organizations should consider all data sources and computing services as resources.
  • They should secure all communication regardless of network location.
  • They should grant access to individual enterprise resources on a per-connection basis.
  • They should determine access to resources using policy, including the state of the requesting system and user identity, plus other behavioral attributes.
  • They should ensure all systems (owned and associated) are in a secure state and monitor them to ascertain they remain protected.
  • Enterprises should strictly enforce user authentication before giving access. It’s a constant cycle of access, scanning and evaluating threats, adapting, and continually authenticating.

Zero Trust Technology

There are a few technologies and considerations organizations need to implement an efficient and effective zero trust architecture. These include:

  • Zero Trust Network Access: ZTNA Allows new zero trust cloud services to give remote workers and teams access to internal private networks without the risks, complexities, and bottlenecks of Virtual Private Networks (VPNs).
  • Next-Generation Firewall: This tool provides network protection, assists with micro-segmentation, and decrypts traffic.
  • Data Loss Prevention (DLP): This enables organizations to go beyond merely controlling user and device access to managing data use.
  • Continuous Monitoring: Organizations must assume the presence of malicious actors within and outside their networks, so they need technologies that enable continuous monitoring of their systems and data.

Why is Zero Trust Important?

The dawn of the zero trust model was a response to a borderless digital world where innovations like cloud technologies, bring your own device (BYOD), and even the internet of things (IoT) shape the landscape of organizations worldwide. Today, users can work remotely from any device and collaborate online via network sharing and cloud-based SaaS tools.

Organizations store information in the cloud, making it accessible anywhere, while personal devices have flooded the market and found their way into companies’ trusted internal networks. As the world becomes more interconnected, it has led to the disappearance of digital borders, increased cybersecurity threats, and shifted the virtual trust perimeter to end devices and user accounts.

For hackers, it is now easier to target individual employees and personal devices using a phishing scheme (such as social or email phishing) to gain access to private networks than it is to take on the secured networks directly.

Therefore, the premise of zero trust is avoiding granting any device or user implicit trust. Instead, the network must verify such trust before granting access with regular re-evaluation. Furthermore, the model consists of a set of technologies facilitating constant trust evaluation and the control of digital devices, identities, and services.

How to Implement Zero Trust Security

Organizations need to plan and implement a zero trust security model to help advance their cybersecurity and discover the benefits of an evolving zero trust paradigm. 

Follow this six-step zero trust implementation plan to ensure your bases are covered:

1. Rally a Dedicated Zero Trust Security Team

First, organizations need to identify and rally a dedicated zero trust security team tasked with planning and implementing the zero trust migration. The team could include members pooled from IT teams or departments such as applications and data security, user and device identity, and network and infrastructure security.

2. Assess the Environment

The next step involves taking a comprehensive inventory of the devices that have access to the network. The list should include both privately-owned and organization-owned devices. Then, they should go a step further and understand the devices’ security status and controls.

The organization can further look at software resources and users, including accounts, groups, group memberships, identities, non-human identities (apps and service accounts), and virtual machines and containers.

3. Define the Protect Surface

It is not viable or advisable to try and reduce an organization’s expanding attack surface, given today’s fast-evolving threat landscape. However, IT team personnel can identify and define the organization’s protect surface, encompassing the following:

  • Data: Protected health information (PHI), Credit card information (PCI), intellectual property (IP), and personally identifiable information
  • Assets: Medical equipment, SCADA controls, manufacturing assets, IoT devices, and point-of-sale terminals
  • Services: DNS, Active Directory, and DHCP
  • Applications: Custom software

The organization can then move its controls to secure the protected surface and create a security perimeter with limited, precise, and understandable policy statements.

4. Review the Available Zero Trust Technology

NIST identifies three primary approaches to implementing zero trust models. These are micro-segmentation, software-defined perimeter, and enhanced identity governance – IAM and PAM (Identity Access Management and Privileged Access Management, respectively). 

Essential technology you may need includes Zero Trust Network Access (ZTNA), next-generation firewalls, and Data Loss Prevention (DLP), among others.

5. Plan Your Zero Trust Security Strategy

Zero trust networks are customized and constructed around an organization’s protected surface. An example zero trust network configuration plan :

  • Start with multi-factor authentication and single sign-on (SSO) to take your cybersecurity system perimeter-less, especially as the world increasingly incorporates the adoption of software-as-a-service by a remote workforce.
  • Move to privileged access to prevent hackers from logging into the system and moving laterally. Vaulting and randomizing passcodes for highly privileged accounts deters against such tactics.
  • Include a next-generation firewall as a segmentation gateway that creates a micro-perimeter around the identified protect perimeter. Here, you can enforce additional inspection and access control layers.

After architecting a zero trust network, organizations will need sound policies to safelist resources and access levels. Create a high level of granular policy enforcement to ensure only allowed traffic and legitimate applications communication occur.

6. Monitor and Maintain the Network

The final step includes reviewing internal and external logs, focusing on zero trust’s operational aspects. Because it is an iterative process, organizations will need to inspect and log all traffic to get valuable insights into how effective the network is and improve it over time.

The Benefits of Zero Trust Security

The primary benefit of a zero trust approach is it offers protection from all sides – within and outside the network. Traditional security models are failing organizations because they focus defense on the network perimeter. In contrast, many breaches occur from within the network. For example, it could be explicitly from employees or by external threats that infiltrate the network through VPN connections, email, browsers, endpoints, and other means.

Therefore, zero trust security takes away access from everyone until the protected network can ascertain authorized users. It then continuously monitors how users use data and potentially revoke permissions to copy or delete data elsewhere.

IT teams can design zero trust capabilities into business processes, systems, and services, making them better equipped to:

  • Prevent data breaches and use application micro-segmentation to contain lateral movement.
  • Expand security protection across computing and containerized environments, utterly independent of the underlying infrastructure.
  • Continuously monitor and respond to threats or signs of compromise. It logs, reports, alerts against threats and reacts accordingly.
  • Gain visibility into users, components, devices, and workloads, identifying what is running or accessed, and enforcing policies.
  • Ensure the organization’s security while providing a consistent user experience.
  • Reduce full-time equivalent hours and architectural complexities.

Zero trust security models also simplify IT management, optimize for existing IT and security personnel, secure remote workforces, ensure continuous compliance, streamline user access, and give senior management peace of mind.

Challenges of Zero Trust Security

It is not easy to achieve a complete zero trust state, and it’s challenging to find one solution or technology that resolves the different issues involved in achieving a zero trust digital environment in many cases. It is a journey that requires incremental steps and not a one-and-done effort.

Some of the challenges of zero trust implementation include:

  • Micro-segmentation, a foundational concept of zero trust, is challenging to achieve, particularly in on-premises networks and servers managed by legacy firewall technologies.
  • Many organizations and businesses use mixed digital environments. They have infrastructures hosted on-premises and in public and private clouds. They also have remote employee devices hosted anywhere.
  • Organizations using legacy access to web service must upgrade to newer versions - providing constant security and ensuring compliance assessments for users, devices, and connections.
  • The need for remote users to maintain easy and flexible network access from anywhere requires organizations to apply flexible policies complete with permits, audits, controls, and other actions depending on the security signals the network gathers about a user, device, or connection.
  • Resolving IoT issues remains a challenge because the technologies providing zero trust require an agent installed on end devices, which is still impossible with these devices.
  • There must be robust solutions that enable zero trust technologies to control data security and access in the cloud.

Due to the diversity of solutions and technologies organizations can apply, it is necessary to consider integration to avoid overlapping functionality. It will also minimize costs and reduce support and maintenance complexity.

The Bottom Line

As cyberattacks against organizations increase and evolve, traditional “trust but verify” network cybersecurity approaches are no longer enough to deter attacks and protect data and systems. Security teams should understand that implicitly trusting endpoints, devices, and users within their network puts the entire organization at risk from malicious actors, unauthorized users, compromised accounts, and careless insiders.

Therefore, a zero trust security model is critical to secure the organization. The “never trust, always verify” security approach and principles of least privilege and micro-segmentation provide better protection against the ever-evolving and expanding cyber threat landscape.

Zero trust allows organizations to implement better access control, contain breaches, protect their assets, and mitigate the potential for damage. However, without a carefully planned architecture and strategy, it all might end up wasting efforts and resources.


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