Security is protection from, or resilience against,
potential harm (or other unwanted
coercion).
Beneficiaries (technically
referents) of security may be persons and social groups, objects and institutions, ecosystems, or any other entity or phenomenon vulnerable to unwanted change.

Security mostly refers to protection from hostile forces, but it has a wide range of other senses: for example, as the absence of harm (e.g.,
freedom from want
The right to an adequate standard of living is listed as part of the Universal Declaration of Human Rights that was accepted by the General Assembly of the United Nations on December 10, 1948.United Nations''Universal Declaration of Human Right ...
); as the presence of an essential good (e.g.,
food security
Food security is the state of having reliable access to a sufficient quantity of affordable, healthy Human food, food. The availability of food for people of any class, gender, ethnicity, or religion is another element of food protection. Simila ...
); as
resilience against potential damage or harm (e.g. secure foundations); as secrecy (e.g., a
secure telephone line); as containment (e.g., a
secure room or
cell); and as a state of mind (e.g.,
emotional security).
Security is both a feeling and a state of reality. One might feel secure when one is not actually so; or might feel insecure despite being safe. This distinction is usually not very clear to express in the English language.
The term is also used to refer to acts and systems whose purpose may be to provide security (
security company,
security police,
security forces,
security service,
security agency,
security guard,
cyber security systems,
security cameras,
remote guarding). Security can be
physical and
virtual.
Etymology
The word 'secure' entered the English language in the 16th century.
It is derived from Latin ''securus'', meaning freedom from anxiety: ''se'' (without) + ''cura'' (care, anxiety).
Overview
Referent
A security
referent is the focus of a security policy or discourse; for example, a referent may be a potential beneficiary (or victim) of a security policy or system.
Security referents may be persons or social groups, objects, institutions, ecosystems, or any other phenomenon vulnerable to unwanted change by the forces of its environment.
[Barry Buzan, Ole Wæver, and Jaap de Wilde, ''Security: A New Framework for Analysis'' (Boulder: Lynne Rienner Publishers, 1998), p. 32] The referent in question may combine many referents in the same way that, for example, a nation-state is composed of many individual citizens.
Context
The security context is the relationships between a security referent and its environment.
From this perspective, security and insecurity depend first on whether the environment is beneficial or hostile to the referent and also on how capable the referent is of responding to their environment in order to survive and thrive.
Capabilities
The means by which a referent provides for security (or is provided for) vary widely. They include, for example:
* ''Coercive capabilities'', including the capacity to project coercive power into the environment (e.g.,
aircraft carriers,
handguns,
firearms);
* ''Protective systems'' (e.g.,
lock
Lock(s) or Locked may refer to:
Common meanings
*Lock and key, a mechanical device used to secure items of importance
*Lock (water navigation), a device for boats to transit between different levels of water, as in a canal
Arts and entertainme ...
,
fence,
wall,
antivirus software,
air defence system,
armour
Armour (Commonwealth English) or armor (American English; see American and British English spelling differences#-our, -or, spelling differences) is a covering used to protect an object, individual, or vehicle from physical injury or damage, e ...
)
* ''Warning systems'' (e.g., alarm,
radar
Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...
)
* ''Diplomatic and social action'' intended to prevent insecurity from developing (e.g. conflict prevention and transformation strategies); and
* ''Policy'' intended to develop the lasting economic, physical, ecological, and other conditions of security (e.g.,
economic
An economy is an area of the Production (economics), production, Distribution (economics), distribution and trade, as well as Consumption (economics), consumption of Goods (economics), goods and Service (economics), services. In general, it is ...
reform,
ecological protection,
progressive demilitarization,
militarization).
Effects
Any action intended to provide security may have multiple effects. An action may have a wide benefit, enhancing security for several or all security referents in the context; alternatively, the action may be effective only temporarily, benefit one referent at the expense of another, or be entirely ineffective or counterproductive.
Contested approaches
Approaches to security are contested and the subject of debate. For example, in debate about
national security strategies, some argue that security depends principally on developing protective and coercive capabilities in order to protect the security referent in a hostile environment (and potentially to project that power into its environment, and dominate it to the point of
strategic supremacy). Others argue that security depends principally on building the conditions in which equitable relationships can develop, partly by reducing antagonism between actors, ensuring that fundamental needs can be met, and also ensuring that differences of interest can be negotiated effectively.
Security contexts (examples)
The table shows some of the main domains where security concerns are prominent.
Informational
*
Application security
*
Communications security
Communications security is the discipline of preventing unauthorized interceptors from accessing telecommunications in an intelligible form, while still delivering content to the intended recipients.
In the North Atlantic Treaty Organization ...
*
Computer security
Computer security (also cybersecurity, digital security, or information technology (IT) security) is a subdiscipline within the field of information security. It consists of the protection of computer software, systems and computer network, n ...
*
Data security
*
Digital security
*
Endpoint security
*
Information security
Information security is the practice of protecting information by mitigating information risks. It is part of information risk management. It typically involves preventing or reducing the probability of unauthorized or inappropriate access to data ...
*
Internet security
*
Network security
*
Usable security
Physical
*
Airport security
*
Corporate security
*
Food security
Food security is the state of having reliable access to a sufficient quantity of affordable, healthy Human food, food. The availability of food for people of any class, gender, ethnicity, or religion is another element of food protection. Simila ...
*
Energy security
Energy security is the association between national security and the availability of natural resources for energy consumption (as opposed to household energy insecurity). Access to cheaper energy has become essential to the functioning of modern ...
*
Environmental security
*
Home security
*
Infrastructure security
*
Physical security
Physical security describes security measures that are designed to deny unauthorized access to facilities, equipment, and resources and to protect personnel and property from damage or harm (such as espionage, theft, or terrorist attacks). Physi ...
*
Port security/
Supply chain security
*
Security bag
*
Security print
*
Border security
*
Security seal
Political
*
National security
National security, or national defence (national defense in American English), is the security and Defence (military), defence of a sovereign state, including its Citizenship, citizens, economy, and institutions, which is regarded as a duty of ...
*
Public security
*
Homeland security
*
Internal security
*
International security
''International Security'' is a peer-reviewed academic journal in the field of international and national security. It was founded in 1976 and is edited by the Belfer Center for Science and International Affairs at Harvard University and publis ...
*
Human security
*
Societal security
Monetary
*
Economic security
Economic security or financial security is the condition of having stable income or other resources to support a standard of living now and in the foreseeable future. It includes:
* probable continued solvency
* predictability of the future cash ...
*
Social security
Welfare spending is a type of government support intended to ensure that members of a society can meet basic human needs such as food and shelter. Social security may either be synonymous with welfare, or refer specifically to social insurance ...
The range of security contexts is illustrated by the following examples (in alphabetical order):
Computer security
Computer security, also known as cybersecurity or IT security, refers to the security of computing devices such as
computer
A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...
s and smartphones, as well as
computer network
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...
s such as private and public networks, and the
Internet
The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...
. The field has growing importance due to the increasing reliance on computer systems in most societies. It concerns the protection of hardware, software, data, people, and also the procedures by which systems are accessed. The means of computer security include the
physical security
Physical security describes security measures that are designed to deny unauthorized access to facilities, equipment, and resources and to protect personnel and property from damage or harm (such as espionage, theft, or terrorist attacks). Physi ...
of systems and the
security of information held on them.
Corporate security
Corporate security refers to the resilience of
corporation
A corporation or body corporate is an individual or a group of people, such as an association or company, that has been authorized by the State (polity), state to act as a single entity (a legal entity recognized by private and public law as ...
s against
espionage
Espionage, spying, or intelligence gathering, as a subfield of the intelligence field, is the act of obtaining secret or confidential information ( intelligence). A person who commits espionage on a mission-specific contract is called an ...
, theft, damage, and other threats. The security of corporations has become more complex as reliance on IT systems has increased, and their physical presence has become more highly distributed across several countries, including environments that are, or may rapidly become, hostile to them.
Environmental security
Environmental security, also known as ecological security, refers to the integrity of
ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
s and the
biosphere
The biosphere (), also called the ecosphere (), is the worldwide sum of all ecosystems. It can also be termed the zone of life on the Earth. The biosphere (which is technically a spherical shell) is virtually a closed system with regard to mat ...
, particularly in relation to their capacity to sustain a
diversity of life-forms (including human life). The security of ecosystems has attracted greater attention as the impact of ecological damage by humans has grown.
Home security
Home security normally refers to the security systems used on a property used as a dwelling (commonly including doors, locks, alarm systems, lighting, fencing); and personal security practices (such as ensuring doors are locked, alarms are activated, windows are closed etc.)
Human security

Human security is an emerging
paradigm
In science and philosophy, a paradigm ( ) is a distinct set of concepts or thought patterns, including theories, research methods, postulates, and standards for what constitute legitimate contributions to a field. The word ''paradigm'' is Ancient ...
that, in response to traditional emphasis on the right of nation-states to protect themselves, has focused on the primacy of the security of people (individuals and communities). The concept is supported by the
United Nations General Assembly
The United Nations General Assembly (UNGA or GA; , AGNU or AG) is one of the six principal organs of the United Nations (UN), serving as its main deliberative, policymaking, and representative organ. Currently in its Seventy-ninth session of th ...
, which has stressed "the right of people to live in
freedom
Freedom is the power or right to speak, act, and change as one wants without hindrance or restraint. Freedom is often associated with liberty and autonomy in the sense of "giving oneself one's own laws".
In one definition, something is "free" i ...
and
dignity
Dignity is a human's contentment attained by satisfying physiological needs and a need in development. The content of contemporary dignity is derived in the new natural law theory as a distinct human good.
As an extension of the Enlightenment- ...
" and recognized "that all individuals, in particular vulnerable people, are entitled to
freedom from fear
Freedom from fear is listed as a fundamental human right according to The Universal Declaration of Human Rights, adopted in 1948. On January 6, 1941, United States President of the United States, President Franklin D. Roosevelt called it one of t ...
and
freedom from want
The right to an adequate standard of living is listed as part of the Universal Declaration of Human Rights that was accepted by the General Assembly of the United Nations on December 10, 1948.United Nations''Universal Declaration of Human Right ...
".
Information security
Information security refers to the security of information in any form. Spoken, written, digital, networked, technological, and procedural forms of information are all examples that may be covered in an
information security management scheme. Computer security,
IT security,
ICT security, and
network security are thus all subdomains of information security.
National security
National security refers to the security of a
nation-state, including its people, economy, and institutions. In practice, state governments rely on a wide range of means, including
diplomacy
Diplomacy is the communication by representatives of State (polity), state, International organization, intergovernmental, or Non-governmental organization, non-governmental institutions intended to influence events in the international syste ...
,
economic power, and
military capabilities.
Resource security
"Resource security" refers to the political and
commercial objective of ensuring that supplies of materials needed for the production of goods and the satisfaction of
human needs can be reliably sustained into the future. It involves protecting the supply of such resources as water, energy, food and industrial
raw material
A raw material, also known as a feedstock, unprocessed material, or primary commodity, is a basic material that is used to produce goods, finished goods, energy, or intermediate materials/Intermediate goods that are feedstock for future finished ...
s from risks of
global depletion and risks to national supply incurred by trade restrictions, government or terrorist interference or
market failures. While
critical raw materials such as
rare earth minerals are an important focus of resource security planning, resource security covers a broader range of resources.
Food security
Food security is the state of having reliable access to a sufficient quantity of affordable, healthy Human food, food. The availability of food for people of any class, gender, ethnicity, or religion is another element of food protection. Simila ...
, ensuring that a reliable supply of, and access to, safe and
nutritious food, and
energy security
Energy security is the association between national security and the availability of natural resources for energy consumption (as opposed to household energy insecurity). Access to cheaper energy has become essential to the functioning of modern ...
are important aspects of resource security. Food security is gaining in importance as the world's population has grown and productive land has diminished through overuse and
climate change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
.
The
UK government
His Majesty's Government, abbreviated to HM Government or otherwise UK Government, is the central government, central executive authority of the United Kingdom of Great Britain and Northern Ireland. published a ''Resource Security Action Plan'' for England in March 2012, subtitled "Making the most of valuable resources", responding to concerns raised by businesses and business leaders such as the
Confederation of British Industry (CBI) and the
Engineering Employers' Federation (EEF), and work in this field undertaken by the
House of Commons Science and Technology Committee. The action plan was an interdepartmental initiative for which the
Department for Environment, Food and Rural Affairs
The Department for Environment, Food and Rural Affairs (Defra) is a Departments of the Government of the United Kingdom, ministerial department of the government of the United Kingdom. It is responsible for environmental quality, environmenta ...
(DEFRA) took the lead role as first point of contact for business enquiries.
[DEFRA and BIS]
Resource Security Action Plan: Making the most of valuable materials
published in March 2012, accessed on 5 February 2025
Government and business concerns related to "a range of renewable and non-renewable resources", concentrating on those not already covered by
energy security
Energy security is the association between national security and the availability of natural resources for energy consumption (as opposed to household energy insecurity). Access to cheaper energy has become essential to the functioning of modern ...
and
food security
Food security is the state of having reliable access to a sufficient quantity of affordable, healthy Human food, food. The availability of food for people of any class, gender, ethnicity, or religion is another element of food protection. Simila ...
measures, and especially sought to protect the supply of certain specific metals and materials under supply pressure. A generalised fear of resource insufficiency was felt to be inappropriate: thus
Vince Cable, then
Secretary of State for Business Innovation and Skills, spoke in December 2011 about a public policy approach to resource management: Similarly the ''Action Plan'' notes that in general the issue of "resource security" is not concerned with "scarcity" of resources but with availability, supply constraints and the potential financial and environmental costs of opening up new sources of supply.
EEF, the UK's manufacturers' representation organisation (now
Make UK) issued a report in 2014 entitled ''Materials for Manufacturing: Safeguarding Supply'', along with an appeal to the government seeking action to protect the country's supply of essential materials. The report highlighted "over-reliance on
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
for strategic supplies" as a key issue. The EEF and other partners argued that an "Office of Resource Management" within government "could strategically co-ordinate action across Whitehall". The office would form part of the
Department for Business, Innovation and Skills and maintain an overview of the risks to resource security.
Perceptions of security
Since it is not possible to know with precision the extent to which something is 'secure' (and a measure of vulnerability is unavoidable), perceptions of security vary, often greatly.
For example, a fear of death by earthquake is common in the United States (US), but slipping on the bathroom floor kills more people;
[Bruce Schneier, ''Beyond Fear: Thinking about Security in an Uncertain World'', Copernicus Books, pages 26–27] and in France, the United Kingdom, and the US, there are far fewer deaths caused by
terrorism
Terrorism, in its broadest sense, is the use of violence against non-combatants to achieve political or ideological aims. The term is used in this regard primarily to refer to intentional violence during peacetime or in the context of war aga ...
than there are women killed by their partners in the home.
Another problem of perception is the common assumption that the mere presence of a security system (such as
armed forces
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a ...
or
antivirus software) implies security. For example, two
computer security
Computer security (also cybersecurity, digital security, or information technology (IT) security) is a subdiscipline within the field of information security. It consists of the protection of computer software, systems and computer network, n ...
programs installed on the same device can prevent each other from working properly, while the user assumes that he or she benefits from twice the protection that only one program would afford.
Security theater is a critical term for measures that change perceptions of security without necessarily affecting security itself. For example, visual signs of security protections, such as a home that advertises its alarm system, may deter an
intruder, whether or not the system functions properly. Similarly, the
increased presence of military personnel on the streets of a city after a
terrorist attack
Terrorism, in its broadest sense, is the use of violence against non-combatants to achieve political or ideological aims. The term is used in this regard primarily to refer to intentional violence during peacetime or in the context of war a ...
may help to reassure the public, whether or not it diminishes the risk of further attacks.
Recurring concepts
Certain concepts recur throughout different fields of security:
*
Access control
In physical security and information security, access control (AC) is the action of deciding whether a subject should be granted or denied access to an object (for example, a place or a resource). The act of ''accessing'' may mean consuming ...
– the selective restriction of access to a place or other resource.
*
Assurance – an expression of confidence that a security measure will perform as expected.
*
Authorization – the function of specifying access rights/privileges to resources related to information security and computer security in general and to access control in particular.
*
Cipher
In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode i ...
– an algorithm that defines a set of steps to encrypt or decrypt information so that it is incomprehensible.
*
Countermeasure – a means of preventing an act or system from having its intended effect.
*
Defense in depth – a school of thought holding that a wider range of security measures will enhance security.
*
Exploit (noun) – a means of capitalizing on a vulnerability in a security system (usually a cyber-security system).
*
Identity management – enables the right individuals to access the right resources at the right times and for the right reasons.
*
Password – secret data, typically a string of characters, usually used to confirm a user's identity.
*
Resilience – the degree to which a person, community, nation or system is able to resist adverse external forces.
*
Risk – a possible event which could lead to damage, harm, or loss.
*
Security management – identification of an organization's assets (including people, buildings, machines, systems and information assets), followed by the development, documentation, and implementation of policies and procedures for protecting these assets.
*
Security seal
*
Threat – a potential source of harm.
*
Vulnerability – the degree to which something may be changed (usually in an unwanted manner) by external forces.
See also
*
Peace
Peace is a state of harmony in the absence of hostility and violence, and everything that discusses achieving human welfare through justice and peaceful conditions. In a societal sense, peace is commonly used to mean a lack of conflict (suc ...
*
Safety
Safety is the state of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk.
Meanings
The word 'safety' entered the English language in the 1 ...
*
Security increase
*
Security risk
*
Security convergence
*
Gordon–Loeb model for cyber security investments
Notes
References
External links
*
{{Authority control
Prevention
Law enforcement