Power Failures

Power Failures

by Kelly Standridge


This paper seeks to explain power failures, as an attack mechanism, affect computer systems and critical infrastructures as a whole. Among the definitions of a power failure, are similar types of power-related problems that could be grounds for disrupting information systems. Next is a brief explanation of how power utilities are managed and the effects of failures, along with the nature of this type of incident, from an attack perspective. Lastly are several examples, with very different causes and outcomes, as well as what can be done to secure systems against power failures and implement future preventative measures.


Normally, people think of power failures as a common nuisance during a storm, where high winds may have knocked a power line loose, leaving many without a source of electricity. Many forget how dependent we are on electricity, as it makes our daily lives simpler, convenient, safer and more productive. Power failures as an attack method is not a new phenomenon, but has come of concern with the threat of terrorism. Critical infrastructures rely on electrical power to work correctly, just as power relies on the very same infrastructures for communication, organization and control.


Power failures can be defined as a total loss of utility power, caused by lightning strikes, damaging weather, downed lines, over demands on the power grid, natural disasters, accidents or other events.[1] Such failing electrical power can lead to loss of computer system capability, peripheral use and sometimes requite emergency response, as normal services are disrupted.[2]

There are other types of problems associated with electrical power that could disturb information systems:

Power Sags, which are periods of short-term low voltage activity, caused by the startup of large loads.

Power Surges, that are short-term high voltage episodes, due to the rapid reduction of power loads.

Brownouts are reduced line voltage for extended periods of time, like days or weeks. Intentional reduction in power for conservation or extremely heavy loads cause brownouts.

Electrical Line Noise is a high frequency waveform that piggybacks on the original line. Different types of interference from various utilities cause such noise.

High Voltage Spikes are dramatic increases in voltage, usually caused by lightning strikes.

Frequency Variations are changes in the stability of frequencies, due to generator sites being loaded and unloaded.

Switching Transients occur when the normal durations are shorter than a spike and basically are instantaneous voltage increases.

Harmonic Distortions are warps in the normal waveform, caused by switched mode power supplies and variable speed devices.[1]

Each of these types of power interruption and failure have devastating effects on the information infrastructure. The list of problems include hardware damage, overheating, communication errors, erratic operation, data loss and system crashes.[1] Such imbalances can lead to the partial or whole breakdown of the electric power grid, as the complexity of the grid is mutually dependent on automation systems, computers and networks.[3]

Scope of Power Management and Power Failures

Coordinated with sophisticated controls, networks and operations, there are about 300 independent electric utilities in the United States: 80% of power generated comes from investor-owned utilities, 10% from the federal government (which manages large facilities) and the rest is generated through cooperatives and manufacturing industries.[4] The electric power industry must keep its supply and demand very close at all times, because generation must be matched accurately with real-time demands, or else failures occur.[5] Failures were in mind upon the designing of the power grid, as it can handle certain limited numbers and types of them, within geographical proximity. However, when these failures occur at various points along the grid, they have the potential to severely degrade and corrupt the communications necessary for control.[5] Unintentional power failures certainly pose a risk to computer systems, as do those that are maliciously carried out.

Nature of the Attack

Generally, physical destruction of key infrastructure elements is the largest threat, because such acts directly lead to power failure. Natural forces are the most common type of accidental event that effects power utilities and still remain the top cause of outages.[4] Nature causing power failures is the most easily dealt with; companies and utilities management have experienced outages from storms, floods and other disasters in the past and precautionary measures are implemented from such experience. Facilities and infrastructure elements have been designed to minimize the power losses and react quickly to restore full function to systems.[4] The testing of these response systems occurs periodically as well.

Next to natural hazards, deliberate attacks on the power grid are most threatening and damaging. Physical attacks of this nature are concerned with the destruction and damage of transformers, towers, substations and other structures, which lead to power failure when certain components of the systems are rendered useless. Such structures are targets for criminals, vandals, hobbyists, disgruntled employees, and even cyberterrorists and other foreign intelligence specialists.[3]

Structured electronic attacks can take place on a target's operation systems in order to cause widespread power outages and disruption to a certain geographic area.[4] This, in turn, affects most all resources - schools, financial institutions, traffic control, etc. Utility infrastructure elements have been attacked around the world, for a variety of underlying reasons, but there is evidence that disabling power has been a goal in some of the attacks.


British Airways was affected by a power outage in November of 2003 at Heathrow. Early that morning, a power cut disconnected access to the airline's cargo and departure control systems.[6] The IT staff quickly restored the data center's connections, after the back up power source never started.[7] Eleven flights were cancelled. The global systems were not affected, because the failure was relatively low-scale. The cause of the power failure was a single faulty circuit.[7]

On April 5, 2001, an undetermined problem at Dominion Power in northern Virginia caused America Online to have service problems with its popular Instant Messenger chat program.[8] The power outage swept through the entire region, affecting others besides AOL, which is located in Dulles, VA.

Perhaps the most recent, widespread power outage occurred on August 14, 2003, along the East Coast, Midwest and even into parts of Canada. Nearly a million customers in these areas lost power, due to 21 power plants shutting down.[9] The massive power failure shut down trains and other modes of transportation, affected water supplies, slowed the Internet, and caused glitches in other infrastructure systems.[10] As for the source of the outage, terrorism was ruled out. Some speculate lightning strikes, fires at power plants, or smaller outages could have caused the power failure. Due to the extensive interconnection of all the power grids in the affected areas, the incident was considered a 'cascading' power outage.[9] Power was restored gradually during the few days following the incident.

Animals can also cause power outages, as was the case at Stanford University in October of 1996. Apparently, rats had gnawed through some equipment and caused an explosion, leaving the university without power for two days. Also affected was the BBN Internet hub, disrupting Internet connections for many Silicon Valley companies, as well as the websites of the Los Angeles Times and San Francisco Chronicle.[11]

What can be done?

According to the Institute of Electric and Electrical Engineers, protecting against such means that cause power failures should involve coordinated actions between electrical power system owners and operators, electric power market exchanges, regulators and participants, federal and state law enforcement agencies and the operators behind the communications and control systems that run such utilities.[3] Beyond actively monitoring the power grid, the guarding of control centers (from physical and electronic attacks) through various means, like backup control centers and even separate facilities.[4]

Also, there are multitudes of software, hardware, devices, and procedures that help mediate the effects of a power outage. Among the variety of improvements, the following should be seriously considered:

Conducting security evaluations and audits.

Eliminate security holes (physically and electronically).

Improve communication between operations staff and corporate information security staff.

Establishing security awareness and training programs.

Summary, Conclusions, and Further Work

Experts say that such physical and electronic attacks on power systems not only cause power failures and the effects associated with them, but also expose weaknesses in the information infrastructure. Electrical power is the core of all that requires its services and is increasingly becoming a target of attack, due to its vital role in supporting the function of computers, communications and everyday life. Also, due to the interconnectivity of such power systems, outages or failures in one location can mean the same for locations thousands of miles away. Further work on this topic could possibly be pointed to the mechanisms of electronic attacks in damaging power grids or how the cascading characteristic of power failures could be exploited.


[1]. Bake Electronics: Nine Power Problems and Solutions.

[2]. All.net: Power Failures

[3]. Institite for Electrical and Electronics Engineers: Information Security in Electric Power.

[4]. Information Assurance Task Force: Electric Power Information Assurance Risk Assessment

[5]. CERT: Impedements to Survivability of the Electric Power Grid and Some Collaborative EE-CS Research Issues to Solve Them.

[6]. Computeractive online: "Power failure hits BA's systems".

[7]. ComputerWeekly.com: "Back up power failure hits BA's IT systems".

[8]. InternetNews.com: "Power failure plagues AOL's IM service".

[9]. CNN: "Major power outage hits New York, other cities".

[10]. Computerworld: "Northeast, Canada power failure exposes infrastructure frailty".

[11]. Peter Neumann: Computer Related Risks - New Material