The zero-trust security model is a cybersecurity method that by default prohibits access to an enterprise’s digital resources while granting authenticated users and devices specialized, segregated access to only the applications, data, services, and systems required to perform their duties. Gartner predicts that by 2025, 60% of enterprises will implement a zero-trust security posture.

What is Zero Trust Security?

Zero Trust security is an IT security architecture that involves tight identity verification for any person or device attempting to access resources on a private network, whether they are inside or outside the network perimeter. ZTNA is the primary technology associated with Zero Trust architecture; nevertheless, Zero Trust is a comprehensive approach to network security that includes a variety of principles and technologies.

Simply put, traditional IT network security trusts everyone and everything within the network. Zero trust architecture places no faith in anybody or anything. Traditional IT network security relies on the castle-and-moat model. Castle-and-moat security makes it difficult to gain access from outside the network, but everyone inside is trusted by default. The problem with this approach is that once an attacker gains access to the network, they have free rein over everything inside.

This vulnerability in castle-and-moat security systems is exacerbated by the fact that businesses no longer keep their data in a single location. Today, information is frequently dispersed among cloud vendors, making it more difficult to implement a single security control for a complete network.

Zero Trust security means that no one, inside or outside the network, is automatically trusted, and everyone attempting to obtain access to network resources must verify their identity. This additional layer of security has been found to help avoid data breaches. According to studies, the average cost of a data breach exceeds $3 million. Given that figure, it is not surprising that many firms are keen to implement a Zero Trust security policy.

What Are the Principles Behind Zero Trust?

The zero-trust framework outlines a set of principles for eliminating inherent trust and ensuring security through continuous verification of people and devices.

Continuous monitoring and validation

The philosophy behind a Zero Trust network assumes that there are attackers both within and outside of the network, so no users or machines should be automatically trusted. Zero Trust verifies user identity and privileges as well as device identity and security. Logins and connections time out periodically once established, forcing users and devices to be continuously re-verified.

Least privilege

Another principle of Zero Trust security is least-privilege access. This means giving users only as much access as they need, like an army general giving soldiers information on a need-to-know basis. This minimizes each user’s exposure to sensitive parts of the network.

Implementing least privilege involves careful managing of user permissions. VPNs are not well-suited for least-privilege approaches to authorization, as logging in to a VPN gives a user access to the whole connected network.

Device access control

In addition to controls on user access, Zero Trust also requires strict controls on device access. Zero Trust systems need to monitor how many different devices are trying to access their network, ensure that every device is authorized, and assess all devices to make sure they have not been compromised. This further minimizes the attack surface of the network.

Microsegmentation

Zero Trust networks also utilize microsegmentation. Microsegmentation is the practice of breaking up security perimeters into small zones to maintain separate access for separate parts of the network. For example, a network with files living in a single data center that utilizes microsegmentation may contain dozens of separate, secure zones. A person or program with access to one of those zones will not be able to access any of the other zones without separate authorization.

Preventing lateral movement

In network security, “lateral movement” is when an attacker moves within a network after gaining access to that network. Lateral movement can be difficult to detect even if the attacker’s entry point is discovered because the attacker will have gone on to compromise other parts of the network.

Zero Trust is designed to contain attackers so that they cannot move laterally. Because Zero Trust access is segmented and has to be re-established periodically, an attacker cannot move across to other microsegments within the network. Once the attacker’s presence is detected, the compromised device or user account can be quarantined, cut off from further access. (In a castle-and-moat model, if lateral movement is possible for the attacker, quarantining the original compromised device or user has little to no effect since the attacker will already have reached other parts of the network.)

Multi-factor authentication (MFA)

Multi-factor authentication (MFA) is also a core value of Zero Trust security. MFA means requiring more than one piece of evidence to authenticate a user; just entering a password is not enough to gain access. A commonly seen application of MFA is the 2-factor authorization (2FA) used on online platforms like Facebook and Google. In addition to entering a password, users who enable 2FA for these services must also enter a code sent to another device, such as a mobile phone, thus providing two pieces of evidence that they are who they claim to be.

Why is a Zero Trust Model Important?

Zero trust interest and adoption have skyrocketed in recent years, with a slew of high-profile data breaches pushing the need for improved cybersecurity and the global COVID-19 pandemic creating unprecedented demand for secure remote access technology.

Traditionally, organizations used technology like firewalls to create barriers around corporate networks. In this architecture, an off-site user can access resources remotely by connecting to a VPN, which establishes a secure virtual tunnel through the network. However, complications arise when VPN access credentials are compromised, like in the infamous Colonial Pipeline data incident.

Previously, few people required remote access, as the majority of staff worked on-site. However, organizations now need to support secure remote access at scale, increasing the hazards involved.

Read Also: Top 10 Cybersecurity Threats of 2025 – 2030

Furthermore, the perimeter-based architecture was intended for a time when an organization’s resources were housed locally in an on-premises corporate data center. Most organizations’ resources are now dispersed over private data centers and numerous clouds, disrupting the traditional perimeter.

In short, the traditional approach to cybersecurity is becoming less effective, inefficient, and risky. Unlike perimeter-based security, zero trust enables companies to safely and selectively connect users to apps, data, services, and systems on a one-to-one basis, whether the resources are on-premises or in the cloud, and regardless of where users are working.

Zero trust adoption can provide organizations with the following benefits:

• protection of sensitive data;
• support for compliance auditing;
• lower breach risk and detection time;
• visibility into network traffic; and
• better control in cloud environments.

A zero-trust paradigm also incorporates microsegmentation, a key principle of cybersecurity. Microsegmentation allows IT to isolate network resources in discrete zones, limiting possible dangers and preventing them from propagating laterally throughout the company. Organizations can use zero-trust microsegmentation to secure sensitive systems and data by implementing granular, role-based access controls, avoiding a free-for-all and minimizing possible damage.

In a 2021 measure that might place the federal government at the forefront of zero-trust deployment, the White House issued an executive order directing federal agencies to establish a zero-trust security plan, citing cloud usage and the certainty of data breaches as primary factors. Later that year, the United States Office of Management and Budget (OMB) released a draft strategy for carrying out the presidential directive, while the Cybersecurity and Infrastructure Security Agency (CISA) provided additional guidance in its Cloud Security Technical Reference Architecture and Zero Trust Maturity Model (ZTMM).

How to Implement Zero Trust security

A successful zero-trust deployment necessitates consideration of what the Forrester Zero Trust eXtended (ZTX) model dubbed the “seven pillars of zero trust”:

1. Workforce security
2. Device security
3. Workload security
4. Network security
5. Data security
6. Visibility and analytics
7. Automation and orchestration

OMB’s 2021 paper, which supplements the executive order mandating federal agencies to attain zero-trust goals by the end of 2024, and CISA’s ZTMM, both align with the ZTX pillars, adding “governance” as an eighth pillar.

ZTX and ZTMM are merely two ways to implement zero trust. Both attempt to assist firms in developing and executing a zero-trust strategy. While ZTX is applicable to any organization, the ZTMM was created for federal agencies, but any corporation can use the information to implement a strategy.

The CISA ZTMM also defines three levels of zero-trust adoption:

1. Traditional zero-trust architecture
2. Advanced zero-trust architecture
3. Optimal zero-trust architecture

Once an organization is ready to adopt zero trust, it is highly beneficial to approach it in phases. The following are seven steps to implement zero trust:

1. Form a dedicated zero-trust team. Zero trust is a team sport. Choosing the right team members may mean the difference between success and hardship. For example, when deciding who manages zero-trust deployments, consider who has the most expertise in that specific area. Security teams often develop and maintain a zero-trust strategy. But if deploying zero trust across networking-specific areas — such as managing and configuring network infrastructure tools and services, including switches, routers, firewalls, VPNs and network monitoring tools — then the networking team should take charge.
2. Choose a zero-trust implementation on-ramp. An organization generally approaches zero trust at one particular on-ramp. The three on-ramp options are user and device identity, applications and data, and the network.
3. Assess the environment. Review the controls already in place where zero trust is being deployed, as well as the level of trust the controls provide and what gaps need to be filled. Many organizations may be surprised to hear they have pieces of the zero-trust puzzle already in place. Organizations should start by comparing their current security strategy with this zero-trust cybersecurity audit checklist, based on the ZTMM. It will unveil what zero-trust processes are already in place and where gaps exist that need addressing.
4. Review the available technology. Review the technologies and methodologies needed to build out the zero-trust strategy.
5. Launch key zero-trust initiatives. Compare the assessment with the technology review, then launch the zero-trust deployment.
6. Define operational changes. Document and assess any changes to operations. Modify or automate processes where necessary.
7. Implement, rinse and repeat. As zero-trust initiatives are put into place, measure their effectiveness and adjust as needed. Then, start the process all over again.

Remember that zero trust is a journey, not a destination. Run trials, start small, and then expand deployments. A zero-trust security model requires extensive planning and collaboration, but in the end, it is one of the most significant efforts a company can implement, even if it encounters challenges along the road.

What are the Main Zero Trust Best Practices?

• Monitor network traffic and connected devices: Visibility is crucial in order for users and machines to be verified and authenticated.
• Keep devices updated: Vulnerabilities need to be patched as quickly as possible. Zero Trust networks should be able to restrict access to vulnerable devices (another reason why monitoring and validation are key).
• Apply the principle of least privilege for everyone in the organization: From executives to IT teams, everyone should have the least amount of access they need. This minimizes the damage if an end user account becomes compromised.
• Partition the network: Breaking up the network into smaller chunks helps ensure breaches are contained early, before they can spread. Microsegmentation is an effective way to do this.
• Act as if the network perimeter did not exist: Unless a network is completely air-gapped (a rarity), the points where it touches the Internet or the cloud are probably too numerous to eliminate.
• Use security keys for MFA: Hardware-based security tokens are demonstrably more secure than soft tokens like one-time passcodes (OTPs) sent via SMS or email.
• Incorporate threat intelligence: Since attackers are constantly updating and refining their tactics, subscribing to the latest threat intelligence data feeds is critical for identifying threats before they spread.
• Avoid motivating end users to circumvent security measures: Just as overly strict password requirements incentivize users to recycle the same passwords over and over, forcing users to re-authenticate once an hour via multiple identity factors may be too much, ironically decreasing security. Always keep the end user’s needs in mind.

What are Some Zero Trust Use Cases?

Any firm that uses a network and keeps digital data will most likely consider implementing a Zero Trust architecture. However, some of the most common use cases for Zero Trust are:

Replacing or augmenting a VPN: Many organizations rely on VPNs to protect their data, but as described above, VPNs are often not ideal for defending against today’s risks.

Securely supporting remote work: While VPNs create bottlenecks and can slow productivity for remote workers, Zero Trust can extend secure access control to connections from anywhere.

Access control for cloud and multi-cloud: A Zero Trust network verifies any request, no matter its source or destination. It can also help reduce the use of unauthorized cloud-based services (a situation called “shadow IT”) by controlling or blocking the use of unsanctioned apps.

Onboarding third parties and contractors: Zero Trust can quickly extend restricted, least-privilege access to external parties, who typically use computers that are not managed by internal IT teams.

Rapidly onboarding new employees: Zero Trust networks can also facilitate quickly onboarding new internal users, making them a good fit for fast-growing organizations. In contrast, a VPN may need to add more capacity to accommodate large numbers of new users.