This Research Highlight identifies the key ways that firewalls play a role in establishing zero trust in industrial Operational Technology (OT) environments. It also pinpoints the anticipated spending on OT network security and segmentation technologies through 2028.
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OT Cybersecurity Overview
ABI Research's recent OT Security Markets market data (MD-OTSM-23) highlights that segmentation technologies dominate revenue generation in the OT security market. These technologies are essential for securing OT environments by dividing network architectures into isolated zones or blocking data flows between Information Technology (IT) and OT systems. By 2028, these cybersecurity solutions are expected to generate US$10.7 billion in revenue worldwide. In 2023, OT segmentation technologies, such as firewalls, generated nearly US$3.5 billion, with projections reaching US$6.3 billion by 2028. Their critical role in safeguarding industrial operations makes them the largest area of OT security spending.
The leading markets for network security and segmentation—and, therefore, firewalls—are mining, quarrying, and oil & gas extraction. The high value of commodities drives investment in security to protect revenue streams in these sectors.
In the utilities sector, stringent regulations push companies to allocate specific budgets for cybersecurity. Manufacturing ranks third, with security concerns driven by a mix of regulatory pressures and the need to protect Intellectual Property Rights (IPR). Regulations like the European Union’s (EU) Cyber Resiliency Act (CRA) increasingly require manufacturers to integrate security into their processes.
“Firewalls are an integral component of both network security and segmentation, so these trends indicate a positive outlook for firewall technology deployments in OT environments. A 10.7% Compound Annual Growth Rate (CAGR) in segmentation revenue indicates that organizations are prioritizing network segmentation as a critical security strategy. Firewalls play a crucial role in this by enforcing micro-segmentation, which helps isolate critical assets and limit lateral movement of threats.“ – Michela Menting, Senior Research Director at ABI Research
Understanding Why Firewalls Are Integral to Zero Trust
The zero trust approach of "never trust, always verify" emphasizes least-privilege access, identity verification, and ongoing monitoring in an Operational Technology (OT) setting. This underscores the importance of firewalls as a key element in OT environments, integrating with Identity and Access Management (IAM) systems, while ensuring smooth industrial processes. Firewalls bolster zero trust by establishing traffic control rules, along with Deep Packet Inspection (DPI) and Intrusion Prevention Systems (IPSs) to identify and block unauthorized intrusions or threats within the industrial network.
How Firewalls Are Evolving
Conventional firewalls primarily filter traffic based on preset IP addresses, ports, and protocols, acting as a barrier that limits access to specific network components. In contrast, Next-Generation Firewalls (NGFWs) deliver enhanced capabilities such as DPI, IPSs, application-layer filtering, and Artificial Intelligence (AI)-driven behavioral monitoring. These advanced tools enable deeper, more comprehensive analysis of network traffic, users, and endpoints, making them more effective for today’s industries and sophisticated cyberthreats.
Firewalls can also take advantage of 5G’s enhanced connectivity and resilience in the event that wired connections fail. Furthermore, industrial 5G’s scalability and higher data transmissions will bode well for manufacturers’ digital transformation journeys.
Account for Both Legacy and Modern Systems
Most manufacturers will not dump their legacy software/hardware for security reasons, especially organizations with limited financial resources. Isolating these solutions is also not a viable option, as it would create data silos between OT/IT and lead to downtime. Adopting NGFWs, while not 100% bulletproof like any security tool, is an effective route to take.
A comprehensive OT firewall should support both stateful inspection and DPI, addressing the needs of both outdated and modern systems. Critical features include zero trust policy implementation, Virtual Private Network (VPN) support, industrial protocol compatibility, and dynamic network segmentation options such as Layer 3, Layer 2, Virtual Local Area Network (vLAN) segmentation, and transparent/bump-in-the-wire configurations. This functionality is essential for detecting and neutralizing threats targeting industrial protocols, ensuring system-wide security without sacrificing operational efficiency.
Simplifying Access Control Systems with Firewalls
Implementing secure access to industrial systems under the zero trust model requires granular, continuous access control mechanisms. Firewalls are key in managing this, allowing authorized personnel to define precise traffic rules and protect network integrity. Leading vendors offer intuitive interfaces that simplify secure access and facilitate OT data policy enforcement. However, firewalls demand significant expertise and manpower to operate efficiently, making them one of the more resource-intensive solutions in OT environments.
Key Companies from the Report
Learn More
Firewalls are undoubtedly intertwined with a zero trust approach, ensuring unauthorized users do not gain access to devices, systems, and the wider industrial network. However, the implementation of NGFWs into the OT is no easy task, with ABI Research identifying notable challenges in its recently published report, Firewall Technology Developments in OT Zero Trust Networks. Download it today to learn more about the role of firewalls in OT security, the vendors offering leading solutions, and the challenges to be aware of.
