Shigeki Katayama

Information-theoretic approach to authentication codes for power system communications

The purpose of this study is to realize a practical method of providing cyber security for power system communications. Considering communication requirements needed for Smart Grids, power system communications can be classified into five main categories: real-time protection, supervisory control and data acquisition (SCADA), remote access, demand management system (DMS) and advanced metering infrastructure (AMI) . This paper describes a concept and method of effectively applying information-theoretic cryptography to these power system communications. From the requirements of real-time communication and long-term maintenance of such systems, we explore a novel scheme based on unconditionally secure authentication codes (A-codes) having short authenticators (authentication tags) and a feasible number of keys, and have developed a data format for the scheme. The efficiency of the scheme is illustrated using several examples and experimental results.

Distributed real-time computer network architecture-power systems information model coordinated with agent applications

The authors have defined information models for power systems and devices based on object oriented technology, and designed Global and Local information models. The Global information model is used for EMS/SCADA and power systems operation in the control center, and the Local information model represents the behavior of components and devices in the power station and/or substation. Similar information models are being developed by IEC-TC57 as IEC61970 and IEC61850, and by EPRI as CCAPI and UCA2.0, aiming for standardization of open and multi-vendor systems integrated by cooperating EMS/SCADA systems, or equipment and devices. The information models are based on those of IEC and EPRI, and they are expanded for distributed processing in network environments. The authors implemented IEC61970 as the Global information model and IEC61850 as the Local information model with Java Class library. Also, the authors developed a prototype system that consists of a personal computer (PC) as control center, and 2 PCs as substations, and a network computing terminal with current and voltage sensors as another substation. The authors implemented agent applications for simple SCADA and simulation of the power systems devices (ex. Power Transformer, Circuit Breaker) to evaluate the cooperation between agent applications and the information model, and proved the usefulness of the information model. The authors examined the functional expansions for distributed environments, and clarified their ease of implementation and effectiveness.

Issues overcome in the design and application of IEC 61850-compliant substation automation systems

This paper provides an outline of the IEC 61850 standard, it proposes a configuration policy for IEC 61850-compliant SASs and describes their detailed system configuration. This paper also raises issues to be overcome with regard to the practical use of IEC 61850 and describes methods to ensure that interoperability is maintained for multivendor solutions. In addition, this paper explains the technologies and knowledge required to construct an interoperable system with IEC 61850 learnt from our experience of IEC 61850-compliant verification tests and actual projects in Southeast Asia and the Middle East. This paper also clearly describes appropriate definitions for logical nodes, communication services, optional signal settings and allocation of functions to physical devices that must be carefully considered by the system integrator.

Protection relay systems employing unconditionally secure authentication codes

The purpose of this study is to produce practical cyber security for protection relay systems using communication channels, such as pilot protection schemes or wide area protection systems. This paper describes a concept and method of effectively applying unconditionally secure authentication codes (A-codes) to such protection relay systems. From the requirements of real-time communication and long-term maintenance of protection relays, we propose a novel scheme based on A-codes having short authenticators (authentication tags) and a feasible number of keys. The efficiency of the scheme is shown by several examples of pilot protection systems and wide area protection systems. The performance and the key management of the proposed algorithm are also discussed.

Verification of Distributed Real-Time Computer Network Architecture Associated With Off-The-Shelf and Dedicated Technologies

This paper introduces an architecture for computer communications applied to the operation and maintenance of power systems, the distributed real-time computer network architecture (DRNA). The architecture consists of four functional entities, namely, application programs associated with information models, an adaptation function, a transport function, and network- and security-management functions to achieve seamless, real-time, adaptive, and secure information exchange between distributed power system control devices. DRNA uses off-the-shelf and standardized technologies along with dedicated ones. Through careful application of the technology, an experimental setup of a distributed cooperative voltage-control network was constructed in a power system simulator to verify the architectural concept. The implemented technologies include mobile agents, middleware for prioritized and redundant communication schemes, label-switched and Ethernet-based transport networks, and a secure virtual private network. The experiment demonstrated the effectiveness of DRNA.

Power system communications and information-theoretic cryptography

The purpose of this study is to realize a practical method of providing cyber security for power system communications. Power system communications can be classified into three main categories: real-time protection, supervisory control and data acquisition (SCADA), and remote access. This paper describes a concept and method of effectively applying information-theoretic cryptography to real-time protection and control systems, such as pilot protection schemes, wide area protection systems etc. From the requirements of real-time communication and long-term maintenance of such systems, we propose a novel scheme based on unconditionally secure authentication codes (A-codes) having short authenticators (authentication tags) and a feasible number of keys. The efficiency of the scheme is illustrated using several examples of protection and control systems.

Network Computing Terminal as an Intelligent Information Terminal for Power Systems

Abstract The IT has been progressing rapidly, and all devices can be connected to networks, in order to realize anytime and anywhere computer-supported environment. In such situation, we propose the architecture of NCT (Network Computing Terminal) as an information terminal for power systems, and show some application examples. The NCT exactly acquires the phenomenon generated in power systems as digital raw data, edits it autonomously, and cooperates with other NCTs or PC servers if necessary. It can be applied for broad uses, such as fault analysis, measurement of power quality, and remote maintenance servicing.