ZTA for Access Control in Cloud-Native Applications in Multi-Location Environments

In today's digital landscape, security is paramount, especially for cloud-native applications that are distributed across multiple environments. The National Institute of Standards and Technology (NIST) has published guidance on implementing Zero Trust Architecture (ZTA) specifically for cloud-native applications in multi-location environments, detailed in NIST Special Publication 800-207A. The central claim of this report is that cloud-native applications must buttress network-tier policies with identity-tier policies to achieve zero trust. In this blog post, we’ll unpack the argument of the NIST whitepaper. We’ll begin by defining some key terms: zero trust and cloud-native applications.

Understanding Zero Trust Principles

Zero Trust Architecture is built on the principle of "never trust, always verify." This means that no entity, whether inside or outside the network, is trusted by default. Instead, every access request must be authenticated and authorized based on strict identity verification and contextual analysis.

Key Components of Cloud-Native Applications

Cloud-native applications are made up of microservices and often a service mesh. Microservices are independent components that can be hosted on different machines and geographic locations. A service mesh is a software platform that manages communication between microservices, providing services such as discovery, networking, resilience, and security.

Policy Framework for ZTA

The key claim of the NIST paper is that to implement ZTA in cloud-native environments, a comprehensive policy framework is required. This framework should encompass both network-tier policies and identity-tier policies.

• Network-Tier Policies: policies that govern the segmentation and isolation of networks using parameters like IP addresses and subnets. However, they are not sufficient alone to meet Zero Trust principles.

• Identity-Tier Policies: policies that establish trust based on the identity of users and services, independent of their network location. Identity-tier policies are crucial for achieving granular control and enforcing Zero Trust principles throughout the application. Let’s explore identity-tier policies in some more detail.

Advantages of Identity-Tier Policies

Identity-tier policies offer several advantages over traditional network-tier policies. These include service-level segmentation, contextual access control, and scalability and flexibility.

• Service-Level Segmentation: They enable fine-grained control over service interactions, crucial for cloud-native applications.
• Contextual Access Control: These policies take into account the behavior and context of access requests, enhancing security by ensuring that only legitimate requests are granted access.
• Scalability and Flexibility: Identity-based policies are more adaptable to the dynamic nature of cloud environments, where services and users frequently change.

However, while identity-based policies are powerful, they cannot be exclusively used to provide zero trust security for cloud-native applications.

Implementing Multi-Tier Policies

The NIST guidance emphasizes the importance of combining (more dynamic) identity-tier policies with (more static) network-tier policies to create a robust Zero Trust environment. The implementation involves:

• Service Mesh Role: Ensuring secure and resilient communication between microservices.
• Identity Management: Creating and maintaining service identities and issuing authentication and authorization tokens.
• Monitoring Framework: Continuously monitoring the integrity and security posture of all resources, processing data to improve policy creation and enforcement, and providing context for access requests.

Practical Implementation Steps

To effectively implement Zero Trust in a cloud-native environment, organizations should follow these steps:

1. Inventory Resources: Identify all resources, including data, applications, services, and users. This helps in defining clear security perimeters.
2. Define Policies: Develop and document network-tier and identity-tier policies. Ensure they align with organizational goals and compliance requirements.
3. Deploy a Service Mesh: Implement a service mesh to manage microservice communication and enforce security policies.
4. Implement Strong Authentication: Use multifactor authentication to verify user identities robustly.
5. Continuous Monitoring: Establish a continuous monitoring framework to detect and respond to anomalies in real-time.

Conclusion

NIST SP 800-207A provides a detailed framework for implementing Zero Trust Architecture in cloud-native application environments. By leveraging a combination of network-tier and identity-tier policies, enterprises can ensure robust security and adherence to Zero Trust principles, ultimately protecting their applications and data in a multi-cloud and hybrid environment.

Please reach out if you have any questions about how to implement zero trust in your organization.