Cybersecurity Compliance in the Energy Sector: ISO/IEC 27019 Requirements

In the energy sector, where operational technology (OT) systems control critical infrastructure, cybersecurity is paramount. ISO/IEC 27019 provides tailored guidance to secure these systems, ensuring the reliable production and distribution of energy.

What is ISO/IEC 27019?

ISO/IEC 27019 is an international standard that extends the information security controls outlined in ISO/IEC 27002 to meet the specific needs of the energy utility industry. It addresses the unique requirements of process control systems involved in the generation, transmission, storage, and distribution of electric power, gas, oil, and heat.

Developed to bridge the gap between general IT security standards and the specialized needs of energy utilities, ISO/IEC 27019 provides sector-specific measures for securing process control systems. It applies to organizations responsible for energy production and distribution, excluding nuclear facilities, which are covered by separate standards.

While not legally binding, ISO/IEC 27019 is often adopted voluntarily or mandated by regulatory bodies to enhance cybersecurity in critical infrastructure. Compliance demonstrates a commitment to best practices in securing energy systems against cyber threats.

Main Cybersecurity Requirements of ISO/IEC 27019

ISO/IEC 27019 is not a generic checklist; it provides actionable cybersecurity guidance tailored to the operational realities of energy production and distribution environments. Its primary focus is to adapt established information security principles to the specific technical, physical, and functional challenges found in OT and process control networks.

Access Control for Process Control Systems

The standard mandates strict access management policies to ensure only authorized personnel can interact with critical systems. This includes multi-factor authentication, role-based access controls, and the separation of duties, all of which help reduce the risk of insider threats or accidental misuse. Remote access, where necessary, must be implemented with layered protections and comprehensive auditing.

Secure Network Segmentation

ISO/IEC 27019 emphasizes the importance of isolating OT networks from external systems, especially IT environments and third-party connections. Segmentation should be enforced using firewalls, demilitarized zones (DMZs), or unidirectional gateways to prevent lateral movement in the event of a breach.

Protection of System Communications

The integrity and confidentiality of communications between process control components must be ensured. The standard recommends the use of encrypted protocols, integrity checks, and mechanisms to prevent spoofing or unauthorized data injection into control networks.

Patch and Vulnerability Management

Although legacy systems are prevalent in the energy sector, the standard still requires organizations to assess and address known vulnerabilities. Where patching is not possible, compensating controls — such as network isolation, filtering, or unidirectional data flow — must be implemented to reduce exposure.

Monitoring and Incident Detection

Continuous monitoring of OT assets, network traffic, and system logs is required to detect anomalies and security incidents in real time. ISO/IEC 27019 encourages the use of intrusion detection systems (IDS), behavioral analytics, and centralized security event logging to gain visibility into the control environment.

Data Integrity and Availability Safeguards

Critical control data and configurations must be protected against unauthorized modification or deletion. The standard calls for the use of checksums, secure backups, and redundancy strategies to ensure that key systems can continue operating even during or after a cyber event.

System Hardening and Secure Configurations

ISO/IEC 27019 promotes minimizing the attack surface of control systems by disabling unnecessary services, restricting network ports, and enforcing secure default configurations. This is especially important for embedded devices and legacy equipment that may have limited built-in protections.

Management of Third-Party and Remote Interfaces

Energy systems often rely on vendors and service providers for maintenance, diagnostics, or data integration. The standard requires careful control over these interfaces, including rigorous vetting, contractual security requirements, and technical controls such as jump servers or data diodes.

Key Changes in ISO/IEC 27019:2024 vs. 2017

The 2024 revision of ISO/IEC 27019 introduces significant updates to address evolving cybersecurity challenges in the energy sector:

Alignment with ISO/IEC 27002:2022 Themes

The control structure has been reorganized to align with the four themes introduced in ISO/IEC 27002:2022: Organizational, People, Physical, and Technological. This alignment enhances consistency across the ISO 27000 series and facilitates integration with an organization's Information Security Management System (ISMS).

Introduction of Energy Sector-Specific Controls (ENR)

New controls prefixed with "ENR" have been added to address unique challenges in the energy sector, including:

• Organizational Measures: Risk identification related to external partners and customer data handling.

• Physical Security: Protection of control centers, technical rooms, and remote facilities.

• Technical Measures: Addressing legacy system risks, ensuring safety-related function availability, and securing communication links.

• New Requirements: Incorporation of threat intelligence, configuration management, data management, and anomaly detection.

Enhanced Applicability to Modern Energy Systems

The standard now explicitly covers advanced metering infrastructure (AMI), smart grids, distributed energy resources (DER), and electric vehicle charging infrastructures, reflecting the evolving landscape of energy utilities.

Improved Integration with ISO/IEC 27001

By aligning its control structure with ISO/IEC 27002:2022, ISO/IEC 27019:2024 facilitates easier integration into an organization's ISMS based on ISO/IEC 27001. This alignment streamlines the implementation and auditing processes, enabling energy utilities to maintain compliance more efficiently.

How DataFlowX Ensures ISO/IEC 27019 Compliance

Complying with ISO/IEC 27019 requires more than surface-level controls; it means implementing resilient, enforceable cybersecurity mechanisms where traditional protections often fall short.

DataFlowX solutions are purpose-built for this challenge. DataDiodeX provides true unidirectional data flow that enforces physical separation between critical OT systems and external networks, effectively supporting the standard’s requirement for secure segmentation. Even in environments where legacy systems cannot be patched, DataDiodeX enables safe data export for monitoring and logging, without creating a path for exploitation. Its integrated features, like CDR for embedded threat removal and protocol validation, ensure that only clean, policy-compliant data ever leaves the protected network.

DataBrokerX extends this security posture by enabling tightly governed, bidirectional communication where operational workflows demand it, such as between control centers and remote substations or partners. With deep protocol awareness, rules-based data transfer logic, and robust authentication controls, it enforces the requirements of ISO/IEC 27019 for access control, integrity assurance, and controlled supplier interaction.

Together, these systems provide more than isolation: they create a secure, auditable interface between OT and IT that supports compliance without compromising performance.

Contact us today to learn how DataFlowX can help your organization achieve ISO/IEC 27019 compliance and secure your energy systems.