Zero trust requires a significant investment of time and financial resources to implement. It requires determining how to effectively segment your network and define access control policies for those segments.
Continuous verification should be assumed, and every device and user should be inspected and authenticated before a connection is granted. This reduces the "blast radius" and minimizes impact if a breach occurs.
Authentication and Authorization
As the name suggests, authentication is the first step in the Zero Trust security model. Just as you must verify your identity to gain access to a bank, the system must authenticate users and determine their permission level to implement Zero Trust network access; you must be able to monitor all traffic and resources on a single, centralized dashboard. This requires a flexible solution with advanced analytics, automated threat detection and response, and workflow-based automation tools to reduce human error and improve efficiency.
The Zero Trust security model assumes that any user, device, or software is a threat and can cause a cyberattack, even devices and systems that are not considered sensitive or privileged. To mitigate this, the Zero Trust architecture uses micro-segmentation to isolate systems and limit the "blast radius" in the event of an attack. It also leverages end-to-end encryption for all communications and enforces business policies based on context. This includes enforcing the least privilege principle, which requires that credentials be restricted to the minimum permissions needed for an application.
The Identity pillar manages and authenticates user identities to provide context for access control policies. This requires a robust identity management system to securely store and manage user credentials and passwords and implement strong authentication requirements like multi-factor authentication (MFA) and risk-based authorization solutions.
Zero Trust Network Access also requires an identity-centric approach to device and user enrolment. This ensures that devices and users are verified and authorized before access to corporate resources. It also ensures access to resources is on a per-session basis and with the least privilege required to complete a business task.
The observability pillar leverages security tools and techniques such as threat intelligence, security information and event management (SIEM), network traffic analysis, endpoint detection and response, and cloud workload protection to monitor and secure networks, applications, and devices. This enables granular visibility and reporting across your digital estate while leveraging AI and ML to identify and respond to threats in real-time with workflow-based automation tools that reduce human error.
The observability pillar takes the philosophy "never trust, always verify" to an extreme. To identify threats, every connection must be verified with security tools such as SIEM, network traffic analysis (NTA), and next-generation endpoint and device technologies. Using these tools, a zero-trust network can create an identity and context-based logical access boundary that acts as a security fence around enterprise apps for end-users who have been properly authenticated and authorized to connect. This logical perimeter can restrict lateral movement and limit privilege escalation.
Zero-trust networks can also ensure data at rest is secure. This is accomplished with encryption, identity management, and advanced threat protection. Encryption can be automated through risk-based multi-factor authentication and security policies for applications, endpoints, and devices.
In addition, the security posture of unmanaged devices, such as those used in BYOD arrangements, must be evaluated and compared to that of managed systems. This is done by deploying robust cloud workload technology that ties company assets to security policies, regardless of where they are deployed.
Encryption is a fundamental component of Zero Trust and helps protect data and services. It's important to ensure that all communications are encrypted, regardless of where they occur – within the firewall, on the public Internet, or in the cloud. This mitigates many common cyberattacks, such as man-in-the-middle attacks and DNS poisoning.
A Zero Trust solution should provide granular visibility and reporting for a comprehensive security posture. It should also allow for continuous access verification, which limits the "blast radius" if a breach happens and requires that unauthorized activity be investigated and responded to in real-time.
Organizations that implement a Zero Trust framework significantly reduce their exposure to cybersecurity risk. However, implementing the framework can be complex and often involves multiple tools that must work together. Using a Secure Access Service Edge (SASE) platform with integrated zero trust capabilities, micro-segmentation, and advanced threat detection and prevention will help speed up the time to deploy and deliver a successful Zero Trust network access deployment. It will also simplify management and increase security efficiency.
As the Zero Trust implementation is rolled out across the organization, it is important to implement automation to scale up and support the new approach. This includes automating the processes that manage authentication and authorization, device health assessment, network traffic analysis, identifying suspicious activity, and more.
This is especially crucial for large organizations, where the risk of an attacker getting inside the network via stolen credentials or malware on a remote worker's computer or mobile device could be significant. Having automated systems that monitor and detect suspicious activity will help limit the damage, even when human eyes can't detect attackers.
Organizations should consider implementing a software-defined perimeter (SDP) to accelerate the Zero Trust implementation process. This provides access to internal applications from the Internet directly from the user's browser or mobile app and bypasses the corporate network, eliminating the need for VPN appliances and the associated management and infrastructure costs. It also enables real-time threat inspection of user and device context and enforces business policies for secure application access. All data should be encrypted in transit and at rest.