What is Zero Trust? Core Principles and Benefits

In the digital age, as traditional network boundaries gradually disappear, Zero Trust Security becomes an essential security method helping businesses deal with increasingly sophisticated threats. No longer relying on the concept of "default trust," Zero Trust focuses on continuous verification, access limitation, and close monitoring, thereby building a solid security foundation for all organizations.

What is Zero Trust?

Zero Trust is a modern security model designed to respond to increasingly sophisticated network threats. Unlike the old approach that defaulted to trusting users or devices within the system, Zero Trust operates on the principle: "Never trust, always verify."

This means that every access request, whether originating from outside or inside the organization, must undergo strict authentication processes and be granted permissions according to the minimum necessary scope.

The biggest difference between Zero Trust and traditional security models lies in how they view "safe zones":

Traditional model (castle-and-moat): focuses on building "firewalls" for external protection; once past the protective layer, internal users are assumed to be safe by default.

Zero Trust: no concept of "internal is trustworthy" exists; instead, the system continuously verifies identity, devices, and behavior to ensure absolute security.

With this approach, Zero Trust provides tighter security capabilities, suitable for the current context of remote work, cloud usage, and distributed infrastructure.

Why is Zero Trust Security Important?

In the increasingly complex cybersecurity landscape, Zero Trust Security has emerged as a strategic pillar, determining the survival and sustainable development capabilities of modern enterprises. The importance of this model can be clearly seen through three key aspects: immeasurable financial impact from data breaches, inherent limitations of traditional security models, and explosive global deployment trends.

1. Terrible Financial Impact from Data Breaches

According to the IBM Cost of Data Breach 2025 report, the average global cost of a data breach has reached a record level of $4.45 million USD, increasing 15% in just three years. In the United States, this figure even exceeds $10.22 million USD per incident. The ASEAN region – including Vietnam – also recorded an average damage of $3.05 million USD, with an annual growth rate of 6%.

Notably, about one-third of costs arise after more than a year from when the incident occurred. In specialized industries like finance and healthcare, up to 47% of breach costs are recorded after the first year. Research also shows that 82% of incidents involve data stored on the cloud, with an average detection and handling time of up to 292 days – a period long enough to cause serious consequences.

2. Serious Limitations of Traditional Security Models

The traditional "perimeter" security model – based on the principle of "trust but verify" – increasingly reveals fatal blind spots in the digital work context. Some typical weaknesses:

Remote work: The COVID-19 pandemic clearly demonstrated risks, when data breach costs for remote-working businesses increased from $3.86 million USD to over $4 million USD.

Internal threats: Defaulting to trust internal users and devices creates a serious "blind spot" – where attackers can easily exploit once they have penetrated the system.

3. Global Zero Trust Adoption Trends

The necessity of Zero Trust has driven a strong deployment wave:

72% of organizations globally are deploying or have specific plans to adopt Zero Trust architecture within the next 2–3 years.
51% of organizations plan to increase security budgets, with Zero Trust as the top priority.
Businesses applying AI and automation in Zero Trust have data breach costs $1.76 million USD lower on average compared to those not yet deployed.

In ASEAN specifically, this benefit is clearly demonstrated with cost savings of nearly $1.25 million USD when applying Zero Trust combined with AI/ML.

Core Principles of Zero Trust Architecture

According to the NIST 800-207 reference framework, Zero Trust architecture is built on the philosophy "Never Trust, Always Verify" and three key principles. This is the foundation helping businesses completely replace the outdated "default trust" model.

1. Continuously Verify

Zero Trust eliminates all assumptions about trustworthiness. All users, devices, or applications must be continuously verified, based on context and risk level at the time of access.

Multi-factor authentication (MFA) and authorization are mandatory requirements.
Risk-conditional access: the system evaluates behavior, location, devices, and security status to make appropriate access decisions.
Real-time monitoring: collects data, detects anomalies, and responds automatically to minimize risks.

2. Limit Blast Radius

This principle stems from the assumption that breaches can occur. Therefore, Zero Trust focuses on preventing spread and minimizing impact:

Micro-segmentation: divides infrastructure into independent zones, applying separate security policies.
Isolation and quick response: isolates suspicious areas, creating time for response teams.
Dynamic control: adjusts access permissions based on current security status and identity.

3. Least Privilege Access

Zero Trust only grants "just enough" permissions to complete tasks, helping limit risks if accounts are compromised.

Detailed authorization: grants permissions according to specific tasks or time rather than broad defaults.
Enhanced RBAC and PAM: controls access based on roles, separates important duties, and specially manages high-privilege accounts.
Continuous authorization: monitors and automatically revokes permissions when detecting anomalies or when tasks are completed.

Benefits of Zero Trust

1. Minimize Data Breach Risks

Zero Trust demonstrates superior effectiveness in preventing and limiting the impact of cyberattacks. Studies show that businesses applying Zero Trust in multi-cloud environments can reduce up to 45% of incidents compared to traditional models.

Prevent lateral movement: Segments systems into independent zones, limiting hackers' deep exploitation capabilities.
Immediate detection and response: Continuous monitoring and verification help detect abnormal behavior promptly.
Protect sensitive data: Encrypts data and controls access in real-time.

2. Enhance Observability and Control Capabilities

Zero Trust allows administrators to have a more comprehensive view of the system.

Continuous monitoring to detect anomalies.
Apply AI/ML to analyze user behavior.
Effective risk management in distributed environments.

3. Support Remote Work Models

In the context of hybrid work and BYOD, Zero Trust ensures security regardless of location.

Control based on identity and devices.
Flexible policies for remote and office work.
Protect personal devices through MFA, VPN, and device control.

4. Improve Compliance

Zero Trust helps businesses meet international standards and regulations such as GDPR, HIPAA, ISO 27001, PCI-DSS.

Strict access control and maintain continuous monitoring.
Provide complete audit trails for auditing purposes.

Conclusion

In today's digital world with increasingly serious security challenges, Zero Trust Security is no longer an option but has become a strategic imperative for business survival and sustainable development.