IEC 62351-9:2023

Overview

IEC 62351-9:2023 is a critical international standard published by the IEC that addresses cyber security key management specifically for power system equipment. This standard focuses on cryptographic key management practices essential for securing data and communications within power systems. It primarily covers the management of long-term asymmetric keys such as public-key certificates and corresponding private keys, forming a foundation for many IEC 62351 services. The scope also extends to symmetric key management for session keys used in group-based communication as applied in IEC 62351-6.

Designed to ensure interoperability across power system equipment and security infrastructures, IEC 62351-9 provides requirements and best practices for managing cryptographic keys in line with organizational policies and regulatory standards. The 2023 revision includes significant technical updates such as enhanced certificate verification, updates to the Group Domain of Interpretation (GDOI), support for Precision Time Protocol (PTP), and new guidelines for cyber security event logging.

Key Topics

• Cryptographic Key Lifecycle Management
  Covers the entire lifecycle of cryptographic keys including generation, distribution, storage, usage, renewal, and revocation, ensuring secure key handling throughout power system operations.

• Public-Key Infrastructure (PKI) and Privilege Management Infrastructure (PMI)
  Details the use of certification authorities (CAs), registration authorities (RAs), and public-key certificates essential for establishing trust and authentication within power equipment communication.

• Symmetric and Asymmetric Key Management
  Addresses both asymmetric key pairs (e.g., public/private keys) and symmetric session keys for securing group communications such as GOOSE and Sampled Values (SV) messages.

• Group Key Management Using GDOI
  Utilizes the IETF-standardized Group Domain of Interpretation (GDOI) protocol for managing group keys, with enhancements supporting power system-specific protocols including IEC 61850 and IEEE 1588 PTP.

• Security Events and Logging
  Defines specific security events relevant to key management and cyber security with recommendations for event logging, supporting integration with IEC 62351-14 for comprehensive security monitoring.

• Future-Proofing for Post-Quantum Cryptography
  While no specific post-quantum measures are mandated yet, the document lays groundwork for potential adoption as quantum computing evolves.

• Integration with Related IEC 62351 Parts
  Focuses on interoperability by aligning key management practices with other parts in the IEC 62351 series governing secure communication protocols such as TLS, DNP3, and more.

Applications

IEC 62351-9:2023 is highly applicable in the following contexts:

• Power Utility Cyber Security
  Ensures secure management of cryptographic credentials protecting control and monitoring systems in electric power utilities.

• Smart Grid Security
  Supports the secure exchange of information across smart grid components including substations, intelligent electronic devices (IEDs), and control centers.

• Industrial Control Systems (ICS)
  Enhances security protocols for critical infrastructure systems that rely on robust key management to prevent cyber intrusions and unauthorized access.

• Interoperability Across Vendors and Systems
  Facilitates consistent key management standards allowing different vendors’ equipment to securely interoperate within a power system environment.

• Regulatory Compliance
  Helps organizations meet compliance requirements relating to cryptographic security and key management defined by international, national, or sector-specific regulations.

Related Standards

For comprehensive security in power system management, IEC 62351-9 complements other IEC 62351 parts and relevant protocols:

• IEC 62351-3: Secure communication using TLS – Profiles TLS options for pairwise symmetric key management.
• IEC 62351-4: Application layer end-to-end security – Specifies security mechanisms for application layer protocols.
• IEC 62351-6: Group communication security – Defines symmetric group key management protocols for GOOSE and SV messages.
• IEC TS 62351-5: Security for IEC 60870-5 and DNP3 protocols – Addresses pairwise communication security.
• IEC 62351-14: Security event logging – Defines requirements and mappings for cyber security event logging.
• IEC/IEEE 61850-9-3: Power Profile for IEEE 1588 (PTP) – Provides precision timing profile, supported in key management by IEC 62351-9.

Adhering to IEC 62351-9:2023 ensures that power system operators and manufacturers implement state-of-the-art cryptographic key management practices, enhancing the overall security posture and trustworthiness of critical power infrastructure communications.