The Challenges (and Solutions!) of Implementing NIST Zero Trust Architecture in Private 5G/LTE Networks

In a few decades, “trust no one” has gone from thriller-movie warnings to mainstream cybersecurity advice. NIST SP 800-207 on Zero Trust Architecture is a required standard in some industries and a best practice almost across the board. No access is given to any enterprise resource – assets, applications, accounts – before authentication and authorization happen and confirm that, indeed, this user and this device should be given this access.

Complying with NIST SP 800-207 on Zero Trust Architecture is not merely about regulatory adherence; it’s about fortifying your enterprise’s security posture. By ensuring that no access is granted to any asset, application, or account without thorough authentication and authorization, you mitigate risks of unauthorized access and potential breaches. This proactive security framework protects sensitive data, enhances operational resilience, and builds trust with partners and customers. In the context of private 5G/LTE networks, implementing NIST Zero Trust principles helps secure high-stakes environments, ensuring your organization can confidently leverage advanced technologies while safeguarding critical resources. Adopting this standard is a strategic move toward sustainable security and operational excellence.

 

When it comes to implementing Zero Trust architecture in private 5G/LTE networks, however, IT and network engineers often hit a roadblock. Cellular networks are different from other enterprise networks in enough critical ways that the standard principles of Zero Trust can’t be implemented in the same manner. But there is hope! This post will go through the major challenges of implementing Zero Trust architecture in private 5G/LTE cellular networks, explain why standard implementation is tricky, and explain how we at OneLayer circumvent the challenges.

 

Challenge: Identifying Identities

One of the main principles of Zero Trust architecture is identity-centric security. All entities in the network, including users and devices, are treated as identities that must be authenticated and authorized.

 

But it’s not easy to pin down a cellular entity’s identity. Is it the device identifier (IMEI)? The SIM? Both of them linked as a unit? And what if it’s a device with multiple SIMs?

 

What about non-cellular devices that connect to the network via a cellular router? Is the router their identity? What if multiple devices connect through the same router – is there a way of telling the devices apart as cellular entities?

 

In order to implement Zero Trust architecture on a private cellular network, you have to first solve the identity crisis.

Solving the Identity Problem with OneLayer Profiling and Fingerprinting

OneLayer enables precise and persistent tracking of individual entities at the device level. To identify devices, OneLayer leverages information shared by the core, coupled with signaling traffic, to create a device fingerprint & profile. The identification of identities isn’t based on only one or even two entity characteristics, but a whole profile of essential details gathered from the cellular core, routers and device signaling patterns. Each unique profile becomes a persistent fingerprint that can be monitored, tracked, and used for security and operations policies such as device authentication and authorization. OneLayer generates OneID, a unique device identifier crucial for precise tracking of both cellular and non-cellular devices, regardless of IP changes or network transitions. OneID facilitates seamless device management and supports micro-segmentation for enhanced network security.

If anything changes about any aspect of the device identity – the SIM, typical signaling patterns – OneLayer can point to the change and raise a question (and answer) about the device’s true identity.

 

By solving the identity crisis effectively, OneLayer enables the identity-centric security essential to Zero Trust architecture implementation.

 

Challenge: Understanding the Context or How to Apply Segmentation?

Several primary principles of Zero Trust architecture revolve around segmentation and enforcement:

 

Micro-segmentation means the network is segmented into smaller zones to limit lateral movement of attackers.

 

Least privilege access segments entities according to their function, and grants only the minimal access to resources required for their function. The accuracy of this segmentation and resulting access permissions is continuously reassessed.

 

Policy enforcement is the practical application of this segmentation, and it needs the context of the device in order to apply segmentation appropriately.

 

But in such a dynamic system, how can you accurately evaluate the context of a given device to segment it appropriately – and do that at scale when you have devices in the thousands or tens of thousands?

Solving the Context and Segmentation Problem with OneLayer

• As mentioned above, OneLayer can profile devices through a proprietary technology that gathers a whole profile of essential details about the device from multiple sources within the network and uses them to create a unique fingerprint for each device. OneLayer also uses these details to understand the current context of the device and to segment it accordingly into the correct policy group.

 

Changes in the device context – locations, identifiers, router connections and other properties – lead to changes in segmentation policies affecting the device. OneLayer uses its understanding of device context to automatically assign the device to policy groups based on its changing properties.

 

OneLayer integrates with network firewalls, providing the firewall with the contextual      information needed in order for it to set and enforce micro-segmentation policies.

 

Challenge: Knowing What Your Devices Are Up to

A Zero Trust-based setup can only work effectively if it has the ability for continuous monitoring and validation of entities on the network. Otherwise, a device that was once authenticated could be tampered with in the future and become a security risk.

 

But the issues with device identification and tracking mentioned above make monitoring a serious challenge on 5G/LTE networks.

Solving the Monitoring Problem with OneLayer

OneLayer follows and notes all the footsteps in real time. All details about every entity are monitored, changes are logged, and the resulting data is continually analyzed for behavioral anomalies and suspicious behavior.

 

OneLayer’s platform has all the information needed to immediately alert on the device behavior. and the appropriate action can be taken.

 

Applying 5G/LTE Cybersecurity Capabilities

 

In November 2024, NIST published a new Cybersecurity White Paper: Reallocation of Temporary Identities: Applying 5G Cybersecurity and Privacy Capabilities.

The NIST paper focuses on enhancing 5G cybersecurity and privacy by detailing how 5G networks protect user identities through dynamic management of temporary identifiers like 5G-GUTI. Unlike previous cellular generations, 5G standards require frequent reallocation of these identifiers to prevent tracking and enhance user privacy. This practice is crucial for network operators and industry stakeholders as it mitigates cybersecurity risks and reinforces user trust by ensuring resilient and secure communications, thereby supporting the broader adoption of 5G technologies in diverse sectors.

OneLayer Bridge Supports the NIST ZTNA Architecture as Follows:

1. Device and SIM Management:
   • OneLayer automates SIM provisioning and device onboarding, aligning with NIST’s emphasis on securing mobile networks by managing device identities and ensuring robust subscriber privacy protections through automation.
2. Visibility and Monitoring:
   • OneLayer offers comprehensive visibility into both cellular and non-cellular devices, which is critical for maintaining security posture and tracking compliance as outlined by NIST. This visibility contributes to the effective management of device identities and the monitoring of device activities.
3. Segmented and Contextual Policy Enforcement:
   • By leveraging Zero Trust architecture, OneLayer ensures that devices are continuously authenticated and authorized, in line with the NIST directives to protect against unauthorized access and track user equipment identities.
4. Integration with Third-party Tools:
   • Through integrations with existing IT/OT security products like firewalls and NAC systems, OneLayer supports NIST’s call for coordinated security measures across various network components, aiding in maintaining a unified and secure 5G/LTE network infrastructure.
5. Comprehensive Alerting:
   • OneLayer’s alerting system parallels NIST’s emphasis on proactively securing 5G/LTE networks. Detailed identity, location-based, and behavior alerts help prevent unauthorized access and data breaches, which aligns with NIST’s focus on preventing tracking and exposure of subscriber activities.
6. Automation and Policy Management:
   • By automating security processes and utilizing detailed device profiles, OneLayer aids in the dynamic reallocation of identifiers and supports the creation and enforcement of policies that control access, consistent with the 5G-GUTI reallocation processes highlighted in the NIST framework.

Overall, OneLayer’s integrated approach to device management, visibility, and security policies enhances the control over mobile network environments, directly supporting NIST’s directives for 5G/LTE cybersecurity and privacy.

 

Building Trust in a Zero Trust World

Zero Trust only means no inherent trust. It keeps risky entities and actions at bay, and extends trust to the right identities in the right situations.

 

Despite the challenges of implementing NIST-defined Zero Trust Architecture in 5G/LTE cellular networks, the solutions are there, valuable and critical.

 

For more information on OneLayer’s Zero Trust architecture solution, visit https://onelayer.com/private-cellular-network-segmentation/