How to Secure Shared Infrastructure Between IT and OT

How to Secure Shared Infrastructure Between IT and OT

The convergence of Information Technology (IT) and Operational Technology (OT) has transformed the industrial landscape, facilitating the optimization of operations while presenting new security challenges. As organizations strive for greater efficiency and agility, securing shared infrastructure becomes paramount. This blog post delves into essential strategies and practices for safeguarding shared infrastructure in environments where IT and OT intersect.

Understanding IT/OT Convergence

The marriage of IT and OT has been evolving since the late 1990s, when the rise of networking technologies allowed for the integration of previously isolated systems. Historically, IT focused on information processing and data management, primarily in office environments, while OT dealt with hardware and software that detects or causes changes through direct monitoring and control of physical devices. The convergence allows for real-time data analytics, but it also broadens the attack surface.

Defining Key Concepts

Shared Infrastructure: This term refers to the resources and components, such as networks, systems, and applications, that are utilized by both IT and OT environments. Shared infrastructure can include cloud services, data analytics platforms, and VPNs. Interoperability: A critical parameter in IT/OT environments, interoperability allows different systems and devices to communicate effectively, which is crucial for informing decision-making across platforms. Segmentation: In the context of network security, segmentation involves dividing the network into smaller, manageable parts to contain potential breaches, limit lateral movement, and improve overall security posture.

Network Architecture for IT/OT Environments

Selecting the right network architecture is essential for successful IT and OT integration. The predominant architectures in industrial environments include:

1. Converged Network Architecture

This approach uses a single network infrastructure to support both IT and OT systems. It promises cost savings and ease of management, yet opens the door to risks associated with a unified security perimeter.

2. Layered Architecture

Layered networks separate OT and IT components while allowing controlled interactions. A common model includes the Purdue Enterprise Reference Architecture (PERA), where layers are defined from enterprise IT (Level 5) to field devices (Level 0). This separation facilitates enhanced security controls tailored to each layer’s unique requirements.

3. DMZ Architecture

A Demilitarized Zone (DMZ) creates a buffer zone where IT and OT can exchange data without exposing the entire network to vulnerabilities. It allows for monitoring and protection of data in transit, effectively segmenting OT networks from external threats.

Enhancing IT/OT Collaboration

A collaborative IT/OT approach is essential to identify and mitigate security risks in shared infrastructures. Here are strategies to improve operational synergy:

1. Establishing Cross-Functional Teams

Creating joint teams that encompass IT, OT, and cybersecurity professionals can facilitate better communication. These teams should meet regularly to discuss ongoing projects, evaluate risks, and share cybersecurity insights.

2. Implementing Common Security Standards

Adopting shared security frameworks, such as the NIST Cybersecurity Framework or ISA/IEC 62443, can help bridge the gap between IT and OT security practices, creating a unified language and consistent protocols.

3. Developing Integrated Incident Response Plans

Incident response plans should encompass both IT and OT scenarios, allowing for coordinated responses. Regular exercises testing these plans can ensure readiness across both domains.

Secure Connectivity Deployment Practices

Secure connectivity is critical when linking IT and OT networks. Here are structured approaches to deploying secure connectivity:

1. Network Segmentation & Microsegmentation

Utilize segmentation to limit access at the level of individual assets or services. Microsegmentation can enforce granular security policies tailored to the specific role of each device, restricting unnecessary access and minimizing exposure to attacks.

2. Robust Authentication Mechanisms

Employ multi-factor authentication (MFA) for all users accessing shared infrastructure. This additional layer of security helps mitigate risks associated with stolen credentials.

3. Encryption of Data in Transit and at Rest

Enforce strong encryption protocols for data in transit (such as TLS) and at rest (like AES), ensuring that sensitive information remains confidential and secure from unauthorized access.

4. Continuous Monitoring & Threat Detection

Implement comprehensive monitoring of network traffic and device behavior. Use intrusion detection systems (IDS) specifically tuned for OT traffic patterns to detect anomalies and potential breaches in real-time.

Historical Context on Key Technologies

The evolution of networking technologies has played a pivotal role in shaping the IT/OT landscape. In the early days of the Internet, proprietary protocols dominated both IT and OT environments, which constrained inter-device communication and created silos.

The introduction of standard communication protocols such as TCP/IP and MQTT has enabled devices from different manufacturers to communicate freely across varied platforms. These standards have been foundational in integrating IT and OT systems, allowing for seamless data flows but demanding robust cybersecurity measures to protect against emerging threats.

Conclusion

As organizations navigate the complexities of shared infrastructure in the IT and OT realms, the emphasis on security cannot be overstated. By implementing robust network architectures, fostering collaboration, and deploying secure connectivity solutions, organizations can mitigate risks while reaping the benefits of convergence. Understanding the historical context of these technologies enhances the ability to leverage them effectively for a more secure operational environment. Vulnerabilities persist, but with deliberate strategies and continuous vigilance, organizations can navigate these complexities while upholding the integrity of their critical industrial operations.