Critical Infrastructure Remote Control Systems and the Terrorist Threat
CRS Report for Congress
Control Systems and
the Terrorist Threat
Updated January 20, 2004
Dana A. Shea
Analyst in Science and Technology Policy
Resources, Science, and Industry Division
Congressional Research Service ˜ The Library of Congress
Critical Infrastructure: Control Systems and the Terrorist
Much of the U.S. critical infrastructure is potentially vulnerable to cyber-attack.
Industrial control computer systems involved in this infrastructure are specific points
of vulnerability, as cyber-security for these systems has not been previously perceived
as a high priority. Industry sectors potentially affected by a cyber-attack on process
control systems include the electrical, telephone, water, chemical, and energy sectors.
The federal government has issued warnings regarding increases in terrorist
interest in the cyber-security of industrial control systems, citing international
terrorist organization interest in critical infrastructure and increases in cyber-attacks
on critical infrastructure computer systems. The potential consequences of a
successful cyber-attack on critical infrastructure industrial control systems range from
a temporary loss of service to catastrophic infrastructure failure affecting multiple
states for an extended duration.
The National Strategy for Securing Cyberspace, released in February 2003,
contains a number of suggestions regarding security measures for control systems.
A focus on the further integration of public/private partnerships and information
sharing is described, along with suggestions that standards for securing control
systems be developed and implemented.
The Homeland Security Act of 2002 (P.L. 107-296) transferred and integrated
several federal entities that play a role in cyber-security of control systems into the
Department of Homeland Security. These entities include the Critical Infrastructure
Assurance Office, the National Infrastructure Protection Center, the National
Infrastructure Simulation and Analysis Center, and parts of the Department of
Energy’s Office of Energy Assurance. Additionally, the Homeland Security Act of
2002 created a new class of information, critical infrastructure information, which
can be withheld from the public by the federal government.
Efforts in increasing the cyber-security of control systems occur both at federal
government facilities and, in critical infrastructure sectors, through industry groups.
The Department of Energy National Laboratories, the Department of Defense, and
the National Institute of Standards and Technology all have programs to assess and
ameliorate the cyber-vulnerabilities of control systems. Industry-based research into
standards, best practices, and control system encryption is ongoing in the natural gas
and electricity sector.
Possible policy options for congressional consideration include further
development of uniform standards for infrastructure cyber-protection; growth in
research into security methods for industrial control systems; assessing the
effectiveness of the new exemptions to the Freedom of Information Act; and the
integration of previous offices in the new Department of Homeland Security.
This report will be updated as events warrant.
In troduction ......................................................1
Current Industrial Control System Vulnerability..........................2
The Magnitude of the Terrorist Threat.................................6
Potential Consequences of a Terrorist Attack............................9
Department of Homeland Security................................11
Department of Energy.........................................12
Department of Energy National Laboratories...................13
National Institute of Standards and Technology.....................14
Department of Defense........................................14
Federal Energy Regulatory Commission...........................14
Identifying Sectoral Interdependencies............................17
Securing Control System Communications.........................17
Securing Legacy Equipment....................................18
Increasing Research and Development Funding.....................18
Increasing Information Sharing..................................18
Oversight of Department of Homeland Security Coordination..........19
Critical Infrastructure: Control Systems and
the Terrorist Threat
This report addresses the cyber-vulnerability of critical infrastructure industries
which regularly use industrial control systems. Industrial control systems may be
vulnerable to infiltration by different routes, including wireless transmission, direct
access to control system computers, exploitation of dial-up modems used for
maintenance, or through the Internet. This report will specifically discuss the
potential for access to industrial control systems through the Internet.
The vulnerability of U.S. critical infrastructure to cyber-attack and catastrophic
failure was brought to light in 1997 in the report of the President’s Commission on
Critical Infrastructure Protection.1 Among other concerns, the computer systems
used to remotely control process equipment were highlighted as specific points of
vulnerability. These systems were updated during the Y2K crisis, but their cyber-
security generally has not been a high priority. The events of September 11, 2001
have heightened the public awareness of the nation’s vulnerability to terrorist attack,
and a National Research Council report has identified “the potential for attack on2
control systems” as requiring “urgent attention.”
Critical infrastructure is defined in the USA PATRIOT Act as those “systems
and assets, whether physical or virtual, so vital to the United States that the
incapacity or destruction of such systems and assets would have a debilitating impact
on security, national economic security, national public health or safety, or any3
combination of those matters.” Several industry sectors considered to be critical
infrastructures use industrial control systems in their daily activities. These
industries could be significantly affected by a cyber-attack targeting industrial control
systems such as supervisory control and data acquisition (SCADA) systems,
distributed control systems, and others. The President’s Commission on Critical
Infrastructure Protection report stated,
From the cyber perspective, SCADA systems offer some of the most attractive
targets to disgruntled insiders and saboteurs intent on triggering a catastrophic
event. With the exponential growth of information system networks that
interconnect the business, administrative, and operational systems, significant
1 Presidential Commission on Critical Infrastructure Protection, Critical Foundations:
Protecting America’s Infrastructures, October, 1997.
2 National Research Council, Making the Nation Safer: The Role of Science and Technology
in Countering Terrorism, June, 2002.
3 Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept
and Obstruct Terrorism (USA PATRIOT) Act, P.L. 107-56, Title X, Section 1016.
disruption would result if an intruder were able to access a SCADA system and
modify the data used for operational decisions, or modify programs that control4
critical industry equipment or the data reported to control centers.
Current Industrial Control System Vulnerability
The most commonly discussed industrial control systems include supervisory
control and data acquisition (SCADA) systems and distributed control systems
(DCS).5 SCADA systems are often used for remote monitoring over a large
geographic area and to transmit commands to remote assets, such as valves and
switches. For example, they can be found in water utilities and oil pipelines, where
they monitor flow rates and pressures. Based on the data that these systems provide,
computer programs or operators at a central control center balance the flow of
material. Generally, SCADA systems process little data internally, instead
performing analysis in a more central location, but are the primary conduits for raw
data to and commands from a control center. They may be vulnerable to
implantation of faulty data and to remote access through dial-up modems used for
Distributed control systems are process control systems, commonly deployed
in a single manufacturing or production complex, characterized by a network of
computers. DCS generally provide processed information to, or a series of
commands from, a central location. For example, at a chemical plant, a DCS might
simultaneously monitor the temperature of a series of reactors and control the rate at
which reactants are mixed together, while performing real time process optimization
and reporting the progress of the reaction. An attack targeting a DCS might cause
extensive damage at a single facility, but might not affect more than the single site.
These process control systems can be interconnected within a single industry as
well. This might be the case in an infrastructure which both transports and processes
material. As an example, the oil and gas infrastructures contain both processing and
refining sites, as well as holding facilities and distribution systems. Refining and
processing sites may utilize DCS in discrete locations. The distribution and holding
facilities might be managed by a SCADA system which collected data from and
issued commands to different geographic sites from a single location.6
4 Presidential Commission on Critical Infrastructure Protection, Critical Foundations:
Protecting America’s Infrastructures, October, 1997.
5 For a simple overview of control system types, see Micrologic Systems, “SCADA Primer,”
found online at [http://www.micrologic-systems.com/primers/scada.htm], or Dan Capano,
“Distributed Control Systems Primer,” Waterandwastewater.com, (2002), found online at
types of control systems, such as programmable logic controllers, exist, but are not explicitly
6 This example was taken from “IT Security for Industrial Control Systems” by Joe Falco,
Keith Stouffer, Albert Wavering, and Frederick Proctor, Intelligent Systems Division,
National Institute of Standards and Technology, available online at
[ ht t p: / / www.i s d.mel .ni st .gov/ document s / f al co/ IT Secur i t yPr ocess.pdf ] .
Industrial control system technologies are often employed in critical
infrastructure industries to allow a single control center to manage multiple sites.
Industrial control systems were originally implemented as isolated, separate
networks.7 They were viewed as secure systems which protected remote locations
from being physically broken into and mistreated. For example, the establishment
of remote control systems in dams reportedly protected against unlawful release of
the dammed water, as no hand-operable valves and switches were accessible.8
The networking of industrial control systems on a greater scale has led to
increased synergy and efficiency, and, due to market needs (e.g. deregulated
markets), real time information from these systems is increasingly important for
commercial purposes. Consequently, industrial control systems are becoming linked
to corporate computer systems, potentially making them vulnerable to cyber-attack
through the Internet. Original control systems were designed to be free standing
networks without Internet access. Therefore, it has been necessary to add network
access capabilities to these legacy systems to integrate them into the corporate
structure. This has created, in the worst cases, a labyrinth of connections which is
perhaps not rigorously constructed for cyber-security or well documented.
Many organizations, including the General Accounting Office, researchers at
several Department of Energy National Laboratories, and private security and
consulting companies, have identified systemic and specific security vulnerabilities
in select process control systems.9 Among these vulnerabilities are poor cyber-
security practices, such as weak passwords, a lack of robust protocols, and
communication in clear text. While some vulnerabilities arise from the manner by
which the process control system is operated, others are believed to be integral to the
control system configuration itself.
Some industrial control systems, including legacy systems, are proprietary, and
contain non-standard architectures and command syntax. This can be considered
both an advantage and a disadvantage. Proprietary systems with esoteric command
structures are often non-intuitive, and could be difficult to operate by an untrained
individual. Incorrect commands could cause no results, and may increase the
probability that the intruder would be noticed and removed from the system.
Additionally, different companies may have different command sets, even if they are
both members of the same industry, as their proprietary systems may have
significantly different structures. Thus, if a hacker or terrorist successfully attacks
one company, that experience may not be valuable for use at the next company.
7 Separation of control system networks from other computer networks still occurs in some
businesses. For an example, see Alex Salkever, “If These Networks Get Hacked, Beware,”
Business Week Online, September 17, 2003.
8 Scott Berinato, “The Truth about Cyberterrorism,”CIO Magazine, Vol. 15, No. 11, March
9 See Statement of Robert F. Dacey, Director, Information Security Issues Before the
Subcommittee on Technology, Information Policy, Intergovernmental Relations, and the
Census, House Committee on Government Reform, “Critical Infrastructure Protection:
Challenges in Securing Control Systems,” GAO-04-140T; and Alan S. Brown, “SCADA vs.
the Hackers,” Mechanical Engineering, December, 2002.
Others assert that many new control systems, as well as upgrades to legacy systems,
are being assembled from commercial, off-the-shelf equipment and software,
providing commonalities across different industry sectors. They point to the needs
of system maintenance and new component integration as leading to similar control
system architectures both within and between critical infrastructure sectors. By
adopting such equipment and software, vulnerabilities that are identified impact all
The degree of integration between control system networks and publicly
accessible networks is difficult to judge from the open literature. This makes
assessment of the vulnerability of critical infrastructure industries from Internet based
attack difficult to know with certainty.10 Faced with an unclear risk, it may be
difficult, from an industry perspective, to justify the additional costs of upgrading
privately-held industrial control systems to higher security standards.11 Current off-
the-shelf industrial control systems have been designed for operational speed and
functionality, rather than for secure operation, and therefore may not have a high
degree of operational security.12 Addition of security requirements may degrade the
performance of these components below operating standards.
Events have shown that utility control system networks may be vulnerable to
cyber-based incidents. Computers at an inactive nuclear power plant in Ohio were
infected by the Slammer worm in January 2003. The infection disabled some
computer functionality, including monitoring systems for portions of the power
plant.13 Also, it has been reported that other control system computers have been
compromised by other viruses.14
Given the uncertain vulnerability level and the potential systemic weaknesses
involved in current off-the-shelf technology, there appears to be little market
incentive to directly increase industrial control systems security. Therefore the
security systems for the corporate network, which block initial intrusion through the
Internet, may be the sole planned protection for the industrial control systems. Such
10 The Department of Energy and the Department of Defense have performed vulnerability
assessments, through “red team” exercises, of some individual stakeholders in critical
infrastructure industries. (Barton Gellman, “Cyber-Attacks by Al Qaeda Feared: Terrorists
at Threshold of Using Internet as Tool of Bloodshed, Experts Say,” Washington Post, June
27, 2002) These detailed results, while provided to the individual stakeholders, are not
widely available. (Joe Weiss, KEMA Consulting, private e-mail communication, September
11 Eric Pianin and Bill Miller, “Businesses Draw Line On Security, Firms Resist New Rules
For Warding Off Terror,” Washington Post, September 5, 2002.
12 Jennifer Alvey, “Digital Terrorism: Holes in the Firewall? Plugging Cyber Security Holes
Isn’t as Easy as Everyone Wants to Think,” Public Utilities Fortnightly, March 15, 2002.
13 It should be noted that the systems infected were monitoring systems, not computers
which control plant operations. Kevin Poulsen, “Slammer Worm Crashed Ohio Nuke Plant
Net,” The Register, August 20, 2003.
14 Dan Verton, “Blaster Worm Linked to Severity of Blackout,” Computerworld, September
an approach has been criticized, as while it may provide initial barriers to intrusion,
it would not reduce any inherent vulnerabilities in the control system network.15
Security analysts also contend that industrial control systems are less obscure
now than when they were initially developed. Foreign utility companies increasingly
use current commercial off-the-shelf industrial control systems, increasing the
international availability of systems and their documentation. Due to the similarity
between these systems and systems installed domestically, potential terrorists need
not break into an American utility to test their plans.16 Instead, preliminary testing
might be performed outside of the United States on equipment held in other
Some security analysts believe that the industrial control system vulnerability
should be addressed before potentially catastrophic events occur, and that techniques
for reducing the vulnerability are already known. They contend that the majority of
attacks on industrial control systems will come through corporate networks, via the
Internet. While standardized information technology protection methods have not
yet been developed specifically for industrial control systems, these analysts contend
that if general network benchmark standards were uniformly applied across corporate
networks, corporate networks vulnerability to intrusion could be reduced by 80-
88%.17 This would indirectly reduce the industrial control systems vulnerability to
intrusion, as routes through the corporate network would no longer be available.
These benchmark standards include disabling unneeded server functionality, patching
known security flaws, and updating programs to the most recent version.
Other security analysts claim that in addition to general network security,
specific protection for industrial control systems must also be established. Such
protection might be addressed by successfully isolating the control system network
from the corporate computer network or by implementing stronger security measures
at known junctions of the two networks. Such an effort might significantly increase
the difficulty of infiltrating the control system network from the Internet.18
In contrast, control systems may have vulnerabilities unrelated to those
associated with corporate networks, and may require more specific protection,
15 British Columbia Institute of Technology, “BCIT Cyber Security Expert Warns U.s.
Congressional Subcommittee of Critical Infrastructure Vulnerabilities,” News Release,
October 10, 2003.
16 Testimony by Timothy G. Belcher, Chief Technology Officer, Riptech, Inc., before the
House Committee on Government Reform, Subcommittee on Government Efficiency,
Financial Management and Intergovernmental Relations, July 24, 2002.
17 Testimony by Alan Paller, Director of Research, The SANS Institute, before the House
Committee on Government Reform, Subcommittee on Government Efficiency, Financial
Management and Intergovernmental Relations, July 24, 2002.
18 Such methods have been reportedly employed by DuPont Chemical Company. Mathew
Schwartz, “Wanted: Security Tag Team,” Computerworld, June 30, 2003.
including against attacks not transiting the corporate network.19 Protecting corporate
networks from intrusion may not address enough of the vulnerable access routes into
industrial control systems. Joe Weiss, Executive Consultant with KEMA Consulting,
asserts that firewalls, intrusion detection, encryption, and other technology need to
be developed specifically for control systems.20
Some companies have taken aggressive steps to protect their industrial control
systems, and are possible examples for how secure industrial control systems can be
established.21 While most security experts agree that critical infrastructure industries
which view secure industrial control systems as a priority can reduce vulnerabilities,
some assert that most critical infrastructure industries are not willing to voluntarily
commit resources, time and effort into reducing these vulnerabilities. Stuart
McClure, President and Chief Technical Officer of the security company Foundstone,
claims, “[Industries] have fallen into the regulation trap. Unless the government
regulates it, they’re not yet taking [security] seriously.”22
The Magnitude of the Terrorist Threat
Some critical infrastructure industry representatives are skeptical that a cyber-23
terror attack would target industrial control systems. Since there are no reported
terrorist cyber-attacks on domestic critical infrastructure industrial control systems
which have caused significant, publicly reported damage, even in cases where
hackers have successfully broken into these systems, industry representatives believe
the cyber-threat to be low. Diane Van de Hei, executive director of the Association
of Metropolitan Water Agencies and contact person for the water utility Information
Sharing and Analysis Center (ISAC), was quoted as saying, “If we had so many
dollars to spend on a water system, most of it would go to physical security.”24
Analysts have also doubted that terrorist groups will use cyber-attacks to affect
critical infrastructure. They point to the lack of documented terrorism-related cyber-
attacks on critical infrastructure as indicative of low threat probability. “It suggests
19 Joe Weiss, KEMA Consulting, private e-mail communication, September 8, 2002.
20 Testimony by Joe Weiss, Consultant, KEMA Consulting, before the House Committee
on Government Reform, Subcommittee on Government Efficiency, Financial Management
and Intergovernmental Relations, July 24, 2002.
21 For example, see Alex Salkever, “If These Networks Get Hacked, Beware,” Business
Week Online, September 17, 2003 and Scott Berinato, “The Truth about
Cyberterrorism,”CIO Magazine, Vol. 15, No. 11, March 15, 2002.
22 Robert Vamosi, “Cyberterrorists Don’t Care About Your PC,” ZDNet Reviews, July 10,
23 Bill Wallace, “Security Analysts Dismiss Fears of Terrorist Hackers,” San Francisco
Chronicle, June 30, 2002.
24 Robert Lemos, “What Are the Real Risks of Cyberterrorism?” ZDNet, August 26, 2002.
that, as so many commentators have noted, that cyberterror or cyberattacks on
infrastructure are an unlikely threat to the security of the United States.”25
Some critical infrastructure companies believe that the potential damage likely
to be caused by a cyber-attack on control systems would be small and manageable
through already existing procedures. Since fluctuations and equipment failure are
part of expected, normal business, plans and procedures for these naturally occurring
events are in place. They assert that the damage caused by cyber-attack would be
similar to that already routinely seen.26
Some industry representatives emphasize that the unfamiliar and uncommon
commands used in legacy industrial control systems will continue to provide as high
a barrier to future destructive attempts as it has in the past.27 While utility industry
leaders agree that they have been the target of millions of cyber-security incidents,
some do not analyze the origin or method of attack. Will Evans, vice president of IT
services at People’s Energy Corp., reportedly claimed, “[A large utility] could have
a million [intrusion] events that need to be analyzed. I don’t think anybody has the
capability to do that in-house.”
Utility industry representatives contend that the vast majority of computer
intrusion events are searches for vulnerable computers in the corporate network by
inexperienced hackers, and, of the dangerous minority actually performed by
experienced crackers, many are focused on economic aspects of the corporate
network rather than the industrial control systems network.28 From the perspective
of critical infrastructure industries, discontented employees who possess inside
information about industrial control systems are a greater security risk than external
attempts to breach security.
There is evidence that al Qaeda is interested in the vulnerabilities of the U.S.
public and private utilities. The discovery in Afghanistan of a computer containing
structural analysis programs for dams, combined with an increase in Web traffic
relating to SCADA systems,29 prompted the National Infrastructure Protection Center
(NIPC) to issue a warning information bulletin.30 An analysis of cyber-attack data
collected during the second half of 2001 showed that the corporate systems of energy
industry companies are attacked twice as often as other industries, and that a large
25 Jim Lewis, CyberAttacks: Missing in Action, Center for Strategic and International
Studies, April 2003.
26 Kevin Poulsen, “Sparks Over Power Grid Cybersecurity,” Business Week Online, April
27 Scott Berinato, “Debunking the Threat to Water Utilities,” CIO Magazine, Vol. 15, No.
28 Bill Wallace, “Security Analysts Dismiss Fears of Terrorist Hackers,” San Francisco
Chronicle, June 30, 2002.
29 Sean Webby, “4 Cities Take Data Off Web; Authorities Remove Info After Hits From
Mideast,” San Jose Mercury News, June 28, 2002.
30 “Terrorist Interest in Water Supply and SCADA Systems,” National Infrastructure
Protection Center, Information Bulletin 02-001, January 30, 2002.
number of these attacks originate from the Middle East.31 Additionally, according
to one expert, these statistics do not reflect intrusions directed at control systems
which lack firewalls or intrusion detection systems, resulting in an under-reporting
of the actual number of attacks.32
There have been examples of individuals specifically breaking into utility
companies’ control systems. The most notable event occurred in Maroochy Shire,
Australia, where, in Spring, 2000, a discontented former employee was able to
remotely access the controls of a sewage plant and discharge approximately 264,000
gallons of untreated sewage into the local environment.33 In 1994, a hacker
successfully broke into the computer system of the Salt River Project in Arizona and
was able to gain access to computers monitoring canals.34 Another example, from
March, 1997, occurred when a teenager in Worcester, MA was able to remotely
disable part of the public telephone switching network, disrupting telephone service
for 600 residents, including the fire department, and causing a malfunction at the
local regional airport.35 Reportedly, an intrusion into the SCADA systems of a global
chemical company occurred where a former employee attempted to disable chemical
operating systems at a production plant.36
Often, it is difficult to assess from public reports to what degree a critical
infrastructure industry has been breached.37 For example, a cyber-break-in at the
California Independent System Operator (Cal-ISO), California’s primary electric
power grid operator, went undetected for 17 days in April, 2001. Greg Fishman, a
representative of Cal-ISO, reported the intruders “never really got close at all to our
operational systems that run the grid.”38 It is not clear what information was
compromised during the intrusion, who the perpetrators were, or what their goal in
gaining access was. To date, there has been no indication that the perpetrators of this
attack were able to access any sensitive information or systems.
31 Dan Verton, “Vulnerability Assessment Triggers Alarms,” Computerworld, January 21,
32 Joe Weiss, KEMA Consulting, private e-mail communication, September 8, 2002.
33 A summary of this event can be found in National Infrastructure Protection Center,
Highlights, 2-03, June 15, 2002.
34 Robert Lemos, “What are the Real Risks of Cyberterrorism?” ZDNet, August 26, 2002.
35 “Juvenile Hacker Charged with Disabling Airport Control Tower Telephones,” Agence
France Press, March 18, 1998.
36 Esther D’Amico, “Cybersecurity Gains Momentum,” Chemical Week, August 21, 2002.
38 Dan Verton, “California Hack Points to Possible Surveillance Threat; Power Grid
Unaffected; Perps Unidentified,” Computerworld, June 18, 2001.
Potential Consequences of a Terrorist Attack
The consequences of an attack on the industrial control systems of critical
infrastructure could vary widely. It is commonly assumed that a successful cyber-
attack would cause few, if any, casualties, but might result in loss of infrastructure
service while control was wrested from the attacker and damage repaired. For
example, a successful cyber-attack on the public telephone switching network might
deprive customers of telephone service while technicians reset and repaired the
switching network. An attack on a chemical or liquid natural gas facility’s control
systems might lead to more widespread physical damage.
Lower probability events include catastrophic infrastructure failure, where the
failure of one part of the infrastructure leads to the failure of other parts, causing
widespread effect. Such failure might occur due to the synergistic effect of
infrastructure industries on each other. A simple example might be an attack on
electrical utilities where electricity distribution was disrupted; sewage treatment
plants and waterworks could also fail, as perhaps the turbines and other electrical
apparatuses in these facilities shut down. On August 5, 2002, the faulty closure of
an emergency valve at one of Singapore’s two natural gas suppliers blocked the flow
of natural gas to seven electrical power plants. As an immediate result, power levels
dropped 30%, and even after reserve power was employed, there was still a 8%39
shortfall. The power outage lasted up to 90 minutes. Several chemical production
plants were forced to shutdown their facilities during the power outage, and required40
several days to restore full production.
Some experts warn of a cascade event, where a terrorist is able to manipulate
control systems and cause catastrophic failure within an infrastructure. Cascade
events can be very damaging, causing widespread utility outages. Twice in 1996,
arcing between high voltage transmission lines and trees resulted in widespread
power outages. On July 2, 1996, a cascade event left 2 million customers in 11 states
and 2 Canadian provinces without power.41 Most service was restored within 3042
minutes. On August 10, 1996, a similar event caused 7.5 million customers in
seven western states and part of Canada to be without power for up to nine hours.43
39 Krist Boo and Tan May Ping, “90-Minute Blackout in Several Areas,” The Straits Times
(Singapore), August 6, 2002, and Krist Boo, “Computer Glitch Behind Worst Blackout in
Decade,” The Straits Times (Singapore), August 15, 2002.
40 Sam Cage, “Power Failure Downs Three Singapore Crackers,” Chemical Week, August
41 Susan Reed, “Massive Power Outage in West Still Unexplained,” CNN, July 3, 1996 and
Bonneville Power Administration, “Tree Triggers Power Outage,” Journal, August, 1996,
found online at [http://www.bpa.gov/corporate/kc/home/journal/96jl/jl0896x.shtml].
42 “Parts of Idaho Darkened by Power Outage, Earlier Western Blackout Traced to Short
Circuit,” CNN, July 3, 1996.
43 John F. Hauer and Jeff E. Dagle, “Consortium for Electric Reliability Technology
Solutions Grid of the Future, White Paper on Review of Recent Reliability Issues and
System Events,” prepared for Transmission Reliability Program, Office of Power
The August 2003 blackout of the northeastern United States and parts of
Canada, also a cascade event, has been invoked as indicative of the potential effects
a successful terrorist cyber-attack on electrical utility control systems.44 While it was
quickly determined that the power outage was not caused by terrorism,45 there were
questions whether control system failure, computer viruses or worms, or operator-
error played roles in the outage.46 It has been suggested by some that the Blaster
worm, which had been contributing to congestion of the Internet, might have
exacerbated the problems faced by utilities leading up to the blackout event.47
The scenario which causes the highest degree of concern among experts is the
combined use of a cyber-attack on critical infrastructure in conjunction with a
physical attack.48 This use of cyber-terrorism could result in an amplification of the
physical attack’s effects. An example of this might be a conventional bombing attack
on a building combined with a temporary denial of electrical or telephone service.
The resulting degradation of emergency response, until back-up electrical or
communication systems can be brought into place and used, could increase the
number of casualties and public panic.
Others believe that the consequences of a cyber-attack on critical infrastructure
would be very limited, and that excessive focus has been given to an unsubstantiated
terrorist threat.49 Cyber-security experts who doubt the effectiveness of such an
attack range in opinion regarding an attack’s impact. Some believe that a cyber-
attack on critical infrastructure control systems, while having some effect, would not
Technologies, Assistant Secretary for Energy Efficiency and Renewable Energy, U.S.
Department of Energy, August 30, 1999.
44 Kevin Maney and Michelle Kessler, “Blackout Prompts Worries About Security of Power
Grid,” USA Today, August 18, 2003; Johanna McGeary, “An Invitation to Terrorists?” Time,
August 16, 2003; Knut Royce, “Tempting Targets for Terrorists,” Newsday, August 17,
August 15, 2003, p. A27.
45 Philip Shenon, “Agency Quickly Concludes No Terrorist Were Involved,” New York
Times, August 15, 2003.
46 “Power Outage Not Internet Worm-Related,” Reuters, August 14, 2003; Dan Verton,
“Blaster Worm Linked to Severity of Blackout,” Computerworld, September 1, 2003; Dan
Verton, “IT Security in Energy Sector Under Scrutiny,” Computerworld, August 21, 2003;
and Dan Verton, “IT Links to Blackout Under Scrutiny”, Computerworld, September 5,
47 Jim Krane, “Computer-heavy Electrical Grid Vulnerable to Hackers, Viruses,” Associated
Press, September 12, 2003.
48 For an overview of this type of scenario, see National Research Council, Making the
Nation Safer: The Role of Science and Technology in Countering Terrorism, National
Academy Press, Washington, DC, 2002.
49 See, for example, Joshua Green, “The Myth of Cyberterrorism,” The Washington Monthly,
November, 2002; and Joris Evers, “CeBIT: Terrorists Won’t Hit the Internet, Panelists
Agree,” Computerworld, March 14, 2003.
be devastating, but rather only have minor impact.50 For example, security managers
in some electric utilities reportedly believe that experience in dealing with natural
disasters and power outages may translate well to recovering quickly from a cyber-
attack.51 Other believe that there could be significant impacts from a successful
attack on control systems, but that such success would be very unlikely.52 Finally,
some believe that while it is possible to use computers to generate high consequence
attacks, it would be much more likely that a terrorist group would resort to a simpler
conventional attack which would yield results of a similar magnitude.53
Department of Homeland Security
The creation of the Department of Homeland Security has centralized within the
Directorate of Information Analysis and Infrastructure Protection a number of offices
related to critical infrastructure control system security: the Critical Infrastructure
Assurance Office (CIAO), the National Infrastructure Protection Center, the National
Infrastructure Simulation and Analysis Center (NISAC), and part of the Department
of Energy’s Office of Energy Assurance.54
CIAO and NIPC were created in response to Presidential Decision Directive No.
63, issued in 1998.55 CIAO coordinated the federal government’s initiatives on
critical infrastructure assurance and promotes national outreach and awareness
campaigns about critical infrastructure protection. NIPC was a national critical
infrastructure threat assessment, warning, vulnerability, and law enforcement
investigation and response agency. Among other programs, NIPC developed the
InfraGard program, which serves as a clearinghouse for information sharing and
analysis for members of critical infrastructure industries.
NISAC was created in 2001 through the passage of the USA PATRIOT Act.
It is charged to “serve as a source of national competence to address critical
50 Steve Alexander, “Some Experts Say Cyberterrorism Is Very Unlikely,” Star Tribune,
February 13, 2003.
51 Michael A. Gips, “They Secure the Body Electric,” Security Management, November 1,
52 Mark Harrington, “In Cyber-Attack, The System Bends, Doesn’t Break,” Newsday,
February 11, 2003
53 Bill Wallace, “Security Analysts Dismiss Fears of Terrorist Hackers,” San Francisco
Chronicle, June 30, 2002; Jennifer Alvey, “Cyber Security: A ‘Virtual’ Reality,” Public
Utilities Fortnightly, September 15, 2003; and Bruce Schneier, “Embedded Control Systems
and Security,” Crypto-Gram Newsletter, July 15, 2002.
54 Homeland Security Act of 2002, P.L. 107-296.
55 Presidential Decision Directive No. 63 set as a national goal the ability to protect the
nation’s critical infrastructure from intentional attacks. For more information regarding this
directive and other critical infrastructure policy, see CRS Report RL30153, Critical
Infrastructures: Background, Policy, and Implementation by John D. Moteff.
infrastructure protection and continuity through support for activities related to
counterterrorism, threat assessment, and risk mitigation.”56 This center is to provide
modeling and simulation capabilities for the analysis of critical infrastructures,
including electricity, oil, and gas sectors.57 It is located at Sandia National
Laboratories and Los Alamos National Laboratory.58
The Department of Homeland Security created a National Cyber Security
Division, located in the Information Analysis and Infrastructure Protection
Directorate, to identify, analyze, and reduce cyber-threats and vulnerabilities;
disseminate threat warning information; coordinate incident response; and provide
technical assistance in continuity of operations and recovery planning.59 This
division has the responsibility for implementing programs for research and
development in cyber-security, using expertise from the Science and Technology
Directorate to provide research and development functions and execution.
The President’s Critical Infrastructure Protection Board has released The
National Strategy to Secure Cyberspace, in which a general strategic overview,
specific recommendations and policies, and the rationale for these actions are
presented.60 This document addresses concerns regarding digital control systems and
SCADA networks, rates SCADA network security as a national priority, and
recommends joint public/private efforts in discovering solutions to potential
vulnerabilities. This strategy identifies the Department of Homeland Security, in
coordination with other federal agencies, as the department responsible for
developing best practices and new technologies to increase SCADA security. Some
cyber-security experts have criticized this plan, claiming that vulnerabilities will
remain because of its lack of enforcement regulations.61
Department of Energy
The Department of Energy’s Office of Energy Assurance has also been involved
in developing techniques to secure energy production and availability.62 Part of this
effort has been the development of “simple, common-sense approaches to improve
56 USA PATRIOT Act, P.L. 107-56, Section 1016.
57 Jennifer Jones, “Models of Mayhem,” Federal Computer Week, September 30, 2002.
58 For more information on NISAC, see [http://www.sandia.gov/CIS/NISAC.htm].
59 Office of the Press Secretary, Department of Homeland Security, “Ridge Creates New
Division to Combat Cyber Threats,” June 6, 2003.
60 The National Strategy to Secure Cyberspace is available for download at the President’s
Critical Infrastructure Protection Board website, found online at
[ http://www.whitehouse.gov/pcipb/ ].
61 Robert Lemos, “Bush Unveils Final Cybersecurity Plan,” CNET News, February 14, 2003.
62 The Department of Energy’s Office of Energy Assurance can be found online at
[ h t t p : / / www.ea.doe.gov/ ] .
the overall level of protection in SCADA and digital control networks.”63 A
document describing a general approach to improving cyber-security in SCADA
systems has been released.64
Department of Energy National Laboratories. The Department of
Energy National Laboratories have developed a series of test bed facilities to test
security measures developed for critical infrastructure. The Idaho National
Engineering and Environmental Laboratory, in conjunction with Sandia National
Laboratory, are developing a SCADA test bed to help identify vulnerabilities and
improve the security and stability of SCADA systems.65 This test bed is part of an
integrated Critical Infrastructure Test Range, which includes cyber security, wireless
communications, power transmission, and physical security testbeds.66 The Pacific
Northwest National Laboratory has developed a Critical Infrastructure Protection
Analysis Laboratory where, among other things, the vulnerability of SCADA systems67
can be determined.
Research into advanced technologies is currently underway at Department of
Energy laboratories to address process control system security. For example, Sandia
National Laboratory under the Laboratory Directed Research and Development
program has been developing secure control systems for the energy industry.68
Research includes new information architectures, cryptographic methods, and
information system security assessments. Much of this work arises from needs
discovered through partnerships with systems manufacturers. While a prototype
system to demonstrate proof of principle has been implemented at the Sandia
National Solar Thermal Test Facility, this system has not been widely implemented
in the field.69 Similar security efforts, though less directly focused on industrial
control systems, are being developed at both Lawrence Livermore National
Laboratory and Los Alamos National Laboratory.
63 Remarks of James F. McDonnell, Director of the Office of Energy Assurance, at a press
conference in Palo Alto, CA, on September 19, 2002.
64 “21 Steps to Improve Cyber Security of SCADA Networks,” Department of Energy, 2002.
65 For more information about the Idaho National Engineering and Environmental
Laboratory’s Critical Infrastructure Protection Program, see online at
[http://www.inel.gov/na tionalsecurity/critical_infrast ructure_protection_program/ ].
66 Personal Communication from Robert Tuttle, Office of Congressional and
Intergovernmental Affairs, U.S. Department of Energy, August 27, 2003.
67 Securing Our Homeland, Pacific Northwest National Laboratory, available online at
[http://www.pnl.gov/main/ sectors/homeland.html ].
68 Rolf Carlson, “Sandia SCADA Program High-Security SCADA LDRD Final Report,”
Sandia Report SAND2002-0729, Sandia National Laboratories, April, 2002.
69 Sandia National Laboratories, “Dish/Sterling Provides Test for Secure Control System,”
Sandia Technology, Vol. 3, No. 1, Spring, 2001.
National Institute of Standards and Technology
The National Institute of Standards and Technology (NIST) has initiatives in
industrial control system security. NIST, in conjunction with a number of industry
groups, federal government agencies, and professional societies, have created the
Process Control Security Requirements Forum to develop process control
information security requirements. Through their Critical Infrastructure Protection
program, the National Institute of Standards and Technology is developing
information security requirements, best-practice guidelines, and test methods for the
process control sector.70 Scientists at NIST are also actively involved in many
Department of Defense
The Department of Defense, through the Combating Terrorism Technology
Support program, provides support for the protection of infrastructure elements. As
part of this program, encryption algorithms for SCADA systems are being developed
and tested with the end goal of providing recommendations to industry regarding
Federal Energy Regulatory Commission
The Federal Energy Regulatory Commission (FERC) is an independent
regulatory agency within the Department of Energy that, among other duties,
regulates interstate commerce in oil, natural gas, and electricity. FERC has published
a final rule related to critical energy infrastructure information. In this rule, critical
energy infrastructure information (CEII) is defined as:
... information about proposed or existing critical infrastructure that: (i) Relates
to the production, generation, transportation, transmission, or distribution of
energy; (ii) Could be useful to a person in planning an attack on critical
infrastructure; (iii) Is exempt from mandatory disclosure under the Freedom of
Information Act, 5 U.S.C. 552; and (iv) Does not simply give the location of the72
Whether or not information falls under the CEII categorization is initially determined
by the companies submitting the information to FERC. Categorization of select
information as CEII may lead to greater information sharing between industry and the
70 For more information on the Critical Infrastructure Protection program and the Process
Control Security Requirements Forum, see [http://www.mel.nist.gov/proj/cip.htm].
71 Office of the Secretary of Defense, Department of Defense, OUSDC Budget Justification
Materials, FY 2004 Budget, PE 0603122D8Z, February 2003.
72 Federal Register, Volume 68, Number 41, March 3, 2003, pp. 9857-9873, at p. 9857.
The FERC has also published a notice of public rulemaking which includes
cyber-security standards for the electric industry.73 This proposed regulation would
require the electric industry to self-certify that they are meeting minimum cyber-
security standards. It has been reported that FERC will likely adopt standards
developed by the North American Electric Reliability Council in the final version of
this regulation.74 The final version of this regulation has not been issued.75
Some industry groups have taken steps towards addressing control system
security, generally as part of an overall cyber-security initiative.76 Some groups have
launched initiatives in developing infrastructure security programs.77 The North
American Electric Reliability Council has developed a set of minimum cyber-security
standards for the electricity industry, as well as guidelines for securing remote access
to critical electric infrastructure.78
Another approach is to develop voluntary best-practices for process control
system security. Several organizations are taking part in such initiatives. For
example, the Instrument Society of America has formed a committee, ISA-SP99, to
develop a series of reports on best-practices and procedural improvements which
would enhance control system security.79 Similar efforts are underway in other
technical societies, including the Institute of Electrical and Electronics Engineers and
the International Electrotechnical Commission, where working groups on process
control systems and their security are established.
Some industry groups have focused on developing near-term solutions to the
legacy equipment security vulnerabilities. For example, the Gas Technology Institute
73 Federal Register, Volume 67, Number 168, August 29, 2002, pp. 55451-55550.
74 “FERC Likely to Adopt Electric Industry’s Cyber Security Standards,” Electric Power
Alert, Vol. 13, No. 14, July 9, 2003, and Rick Nicholson and Terry Ray, “How Tight Is Your
Padlock?” Platts Energy Business & Technology, May 2003.
75 Due to controversies surrounding other provisions of this proposed regulation, questions
have arisen regarding when, or if, this proposed regulation will be promulgated. For more
general information on this proposed regulation, see CRS Report RS21407, Federal Energy
Regulatory Commission’s Standard Market Design Activities by Amy Abel.
76 For example, the chemical sector has begun a Cybersecurity Practices, Standards and
Technology Initiative, which will develop practices and standards and encourage
development of improved security technology. For more information, see online at
[ h t t p : / / www. c i dx.org/ default_CyberSec.asp?Level=2&SecondLevelURL1=/Securit y/ S e c
77 The Electric Power Research Institute, for example, has developed a series of primers
addressing information security within the energy and power industry. For more
information about the Electric Power Research Institute, see [http://www.epri.com].
78 Information on the North American Electric Reliability Council’s efforts in critical
infrastructure protection can be found online at [http://www.nerc.com/cip.html].
79 For more information on ISA-SP99, see online at
[http://www.isa.org/ MST e mplate.cfm?MicrositeID=988&CommitteeID=6821].
has focused on developing cryptographic protection of SCADA communications and
developing a mechanism for retrofitting legacy equipment to handle these encrypted
signals.80 Other groups have increased outreach efforts to improve understanding of
security issues relating to cybersecurity and process control systems.81
The vulnerability of industrial control systems may be reduced through a range
of federal actions. These include the development of standards, either voluntary or
mandatory, for cybersecurity of control systems; identifying and addressing critical
infrastructure interdependencies; developing encryption methods for control systems;
identifying and establishing technologies to address existing vulnerabilities; funding
long-term research into secure SCADA systems; providing for free exchange of risk
information between the federal government, private industry, and other critical
infrastructure sectors; and assessing federal activities in this area.
The federal government could mandate and enforce a uniform security standard
for cybersecurity of industrial control systems, or support the development of
industry developed and based standards. Because of the national importance of
critical infrastructure systems, a uniform standard might be developed, with the input
of advocates, industries and the federal government, which would include the
functionality necessary to protect industrial control systems, while providing for more
secure operation. A voluntary, standards-based approach has been developed for
server operating systems with some success, and a similar mechanism might be used
to develop standards for commercial off-the-shelf control systems.82 Alternately,
processes and specifications currently being developed through industry-led
programs might be generalized across critical infrastructure industries and established
as a voluntary standard. Critics of this approach cite the many different uses of
industrial control systems in different industry sectors as making such a standard
unwieldy. Some experts have expressed concerns that a mandated standard would
be less effective than a voluntary standard, as solutions to new problems could not
be implemented immediately, but would wait for changes to the standard, and that
such a standard may not be uniformly applicable across industry sectors. Others have
stated that there is a need for federal requirements to assure that appropriate attention
is focused on process control system security.
80 See, for example, American Gas Association, “Cryptographic Protection of SCADA
Communications,” AGA Report 12-1, April 2003.
81 For more information about the Partnership for Critical Infrastructure Security working
groups, see online at [http://www.pcis.org/library.cfm?urlSection=WG].
82 The Center for Internet Security, a not-for-profit organization, develops consensus
security standards for computer systems. They can be found online at
[ h t t p : / / www.c i s e c u r i t y.or g/ ] .
Identifying Sectoral Interdependencies
Identifying the dependencies between critical infrastructure sectors, the
vulnerabilities that are present in information technologies in these sectors, and the
possible cross-sectoral impacts of a control system attack may lead to a greater
understanding of the scale of the control system threat. As shown by the August
2003 blackout, the loss of a single infrastructure sector, here the energy sector, may
have serious effects in other critical infrastructures, such as public health and
transportation. Both the Department of Homeland Security, in its role of protecting
infrastructure, and the Department of Energy, in its role of ensuring a robust and
reliable energy infrastructure, perform activities in determining sectoral dependencies
and commonalities. Policymakers may wish to enhance current funding into SCADA
security research, test bed modeling, or critical infrastructure vulnerability assessment
to further clarify the current vulnerability.
Securing Control System Communications
Another option would involve supporting encryption research to protect
industrial control system data transfer. Encrypting the information transmitted
between remote units and their controllers would inhibit inclusion of false
information to and from industrial control systems. Current encryption technology
may not be compatible due to the time required to process the encrypted data and the
level of technology built into control system components. Industrial control systems
have stringent timing requirements and tend to be built out of less computationally
robust components, which complicate the use of current encryption technologies.83
While a prototype encryption method for industrial control systems has been
developed, it is still in the validation process84 and is only recently being evaluated85
for implementation in industry. Further research into encryption techniques for
these processes could provide efficient, market-driven technology for securing
industrial control systems information. Some experts highlight that securing data
transfer does not assure the security of the control system itself. They assert that
other routes of attack exist that do not rely on the security of the control system
communications. Thus, securing those communications, while lowering system
vulnerability, may not be addressing the most likely threat.
83 See, for example, Alan S. Brown, “SCADA vs. the Hackers,” Mechanical Engineering,
84 William F. Rush and John A. Kinast, “Here’s What You Need To Know To Protect
SCADA Systems From Cyber-Attack,” Pipeline & Gas Journal, February 2003.
85 Jennifer Alvey, “Digital Terrorism: Holes in the Firewall? Plugging Cyber Security Holes
Isn’t as Easy as Everyone Wants to Think,” Public Utilities Fortnightly, March 15, 2002;
and American Gas Association, Cryptographic Protection of SCADA Communications –
Draft 2, AGA Report No. 12, January 2, 2004, found online at
[ h t t p : / / www.gt i s er vi ces.or g/ secur i t y/ AGA12Dr a f t 2r 20.pdf ] .
Securing Legacy Equipment
Further research and development into methods for retrofitting existing SCADA
systems with more secure components or communications may be another method
to reduce system vulnerability. This approach has been taken by researchers in both
industry and federal government laboratories. While potentially addressing short
term needs to reduce vulnerability, retrofit solutions are not likely to solve inherent
shortfalls in SCADA security especially with respect to the inclusion of COTS
equipment potentially vulnerable to cyber attack. Critics of retrofit solutions cite
high costs and potential compatibility concerns as barriers to easy implementation of
Increasing Research and Development Funding
A long term approach to limiting the vulnerability of SCADA systems is to
provide further targeted investment into developing “next-generation” secure control
systems. Development of a secure SCADA architecture may provide incentives to
replace components in a secure manner during the normal replacement cycle,
incrementally reducing the present vulnerability. While some argue such product
research and development is a responsibility of private industry, others may assert
that control system security is of national import, requiring enhanced federal
Several National Laboratories have developed complementary testbed facilities
to investigate potential vulnerabilities and solutions to SCADA systems. Such
testbed facilities could be used to evaluate and validate the security of commercial
SCADA systems, act as a proving ground for new technologies, or be dedicated to
the development of federal efforts in secure process control systems.
Increasing Information Sharing
The new FOIA exemptions created in the Homeland Security Act of 2002 (P.L.
107-296) may provide a higher volume, freer exchange of information between the
federal government and industry, as industry may become more forthcoming about
potential vulnerabilities. The Critical Energy Infrastructure Information category for
electrical infrastructure information may provide a model for how regulatory agencies
might craft regulations protecting critical infrastructure information within a sector.
Comments from various groups on the proposed implementation of the Homeland
Security FOIA exemption have indicated that industry concern still remains over the
potential release of information given to the federal government by private industry.86
Policymakers may wish to inquire into whether vulnerabilities transmitted to the
federal government are eventually reduced, and how the information being provided
to the federal government is used.
86 Federal Register, Volume 68, Number 72, April 15, 2003, pp. 18524; and “Businesses
Support Sharing Information on Infrastructure with Federal Agencies,” BNA Daily
Environment Reporter, September 4, 2003, p. A-7.
Oversight of Department of Homeland Security Coordination
Policymakers may also wish to assess the effectiveness of the Department of
Homeland Security in coordinating security enhancements to control systems,
promoting government/industry partnerships, and performing risk and vulnerability
assessments. With the concentration of previously existing agencies into the
Directorate of Information Analysis and Infrastructure Protection, previous
duplication of effort may be removed, but critics have suggested that difficulties in
integrating these agencies may lead to a reduction in effectiveness. Some
policymakers have expressed concern that the priorities DHS have placed on physical
and cyber-security are not appropriate for the risks involved.87 Oversight of DHS’s
efforts to rectify this potential homeland security vulnerability may provide insight
into successful models used within critical infrastructure sectors which might be used
across multiple sectors.
87 “Blackout, Computer Viruses Have Congress Worried,” Gainesville Sun, September 7,