Grid Components and Potential Vulnerabilities
The electric utility business encompasses the process of generating electricity and sending power to the ultimate user. The electrical grid is the name given to the machinery and power lines that enable power to be sent from the power plant to the ultimate user of electricity. As seen in Figure 1, this generally requires an infrastructure made up of generating stations (where the power is produced), step-up transformers and transmission lines (whereby transformers increase the voltage so that the electricity can be sent over very long distances), and step-down transformers and distribution lines (whereby the voltage can be lowered allowing the electricity to be sent to businesses and homes to power machinery and devices). Depending on the regulatory regime in place, these system elements may be controlled by companies under state jurisdiction or entities under federal jurisdiction (such as regional transmission organizations or federal power marketing administrations).
Figure 1: Electric Power System Elements
Source: Congressional Research Service, based on graphic found at https://reports.energy.gov/BlackoutFinal-Web.pdf (p. 5).
Note: kV = kilovolts (or 1,000 volts).
Industrial Control Systems
The grid relies on a number of electronic devices, switches and circuit breakers to regulate and report on the flow of electricity at different parts of the system. Together, these pieces of mechanical and automated equipment constitute the grid’s IC systems, managing power plant controls, transformer yard and power bus1 functions, transmission system, and distribution substations.
The IC system essentially operates in a “control loop” in which sensors continually check key components, with variable responses against control variables in order to ensure that the system is functioning as designed. If responses show a disturbance resulting in operation of the system outside normal operating parameters, then the system adjusts actuators to bring the system back to process norms, or sends alerts to human-machine interfaces 2 (HMIs) to reconfigure the system
1 The bus bar is the point at which electrical power from the power plant is connected to transmission system.
2 “The hardware or software through which an operator interacts with a controller. An HMI can range from a physical control panel with buttons and indicator lights to an industrial PC with a color graphics display running dedicated HMI software.” See Keith Stouffer, Joe Falco, and Karen Scarfone, Guide to Industrial Control Systems (ICS) Security, National Institute of Standards and Technology, NIST Special Publication 800-82, June 2011, http://csrc.nist.gov/
Supervisory Control and Data Acquisition Systems
One IC system used to control remote operations of the power grid is the Supervisory Control and Data Acquisition (SCADA) system.
SCADA systems are highly distributed systems used to control geographically dispersed assets, often scattered over thousands of square kilometers, where centralized data acquisition and control are critical to system operation ... A SCADA control center performs centralized monitoring and control for field sites over long-distance communications networks, including monitoring alarms and processing status data. Based on information received from remote stations, automated or operator-driven supervisory commands can be pushed to remote station control devices, which are often referred to as field devices. Field devices control local operations such as opening and closing valves and breakers, collecting data from sensor systems, and monitoring the local environment for alarm conditions.4
SCADA systems have been in use at least since the 1970s, and were adopted at a time when the focus of system design was on function and reliability. An example of a basic SCADA network is shown in Figure 2. Historically, these systems consisted of remote terminal units5 which were often connected to a mainframe computer via telephone lines or radio connections. They were not typically connected to centralized networks. Utilities typically operated separate control systems created just to operate power plants and related infrastructure.6
Figure 2. SCADA System General Layout
Over time, modification of SCADA systems has resulted in connection of many of these older, legacy systems to the Internet. However, many of these legacy SCADA systems were not designed with security features, allowing other potential pathways for a cyberattack. As a result, these systems may be vulnerable to intrusion through data reporting pathways, or attacks (for example) using a thumb drive to download malware. However, some of these earlier designs and configurations may not be as vulnerable to an Internet-launched cyberattack. The security issue, for old and new systems, then becomes both how they are connected to the utility’s other systems, and what levels of security exist to detect and deter potential intrusions.
Source: See Guide to Industrial Control Systems Security at http://csrc.nist.gov/publications/nistpubs/800-82/SP800-82-final.pdf. Notes: WAN = Wide Area Network; MTU = Master Terminal Unit (server for SCADA system); IED = Intelligent Electronic Device; RTU = Remote Terminal Unit.
4 See Keith Stouffer, Joe Falco, and Karen Scarfone, Guide to Industrial Control Systems (ICS) Security, National Institute of Standards and Technology, NIST Special Publication 800-82, June 2011, http://csrc.nist.gov/publications/nistpubs/800-82/SP800-82-final.pdf. (Hereinafter NISTICS).
5 “RTUs are field devices often equipped with wireless radio interfaces to support remote situations where wire-based communications are unavailable.” NISTICS.
6 Stew Magnuson, “Power Companies Struggle to Maintain Defenses Against Cyberattack,” National Defense Magazine, March 2014, http://www.nationaldefensemagazine.org/archive/2014/March/Pages/ PowerCompaniesStruggletoMaintainDefensesAgainstCyberattacks.aspx.
As the Smart Grid becomes a ubiquitous reality, Cyber Force is here to fix your security problems for today real world.
Smart Grid Networks
Smart Grid networks are also potentially better able to integrate the intermittent energy from renewable electricity technologies (i.e., renewable electricity systems such as distributed solar photovoltaic [PV] and wind), distributed generation, demand response, and consumer energy efficiency programs.7
Source: Consumer Energy Report. See http://www.consumerenergyreport.com/wp-content/uploads/2010/04/ smartgrid.jpg.
7 Department of Energy, Enhancing the Smart Grid: Integrating Clean Distributed and Renewable Generation, 2009, http://energy.gov/sites/prod/files/oeprod/DocumentsandMedia/RDSI_fact_sheet-090209.pdf.