Protecting information by mitigating risk
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 or the unlawful use, disclosure, disruption, deletion, corruption, modification, inspection, recording, or devaluation of information. It also involves actions intended to reduce the adverse impacts of such incidents. Protected information may take any form, e.g., electronic or physical, tangible (e.g., paperwork), or intangible (e.g., knowledge). Information security's primary focus is the balanced protection of data confidentiality, integrity, and availability (also known as the 'CIA' triad) while maintaining a focus on efficient policy implementation, all without hampering organization productivity. This is largely achieved through a structured risk management process. 
To standardize this discipline, academics and professionals collaborate to offer guidance, policies, and industry standards on passwords, antivirus software, firewalls, encryption software, legal liability, security awareness and training, and so forth. This standardization may be further driven by a wide variety of laws and regulations that affect how data is accessed, processed, stored, transferred, and destroyed. 
While paper-based business operations are still prevalent, requiring their own set of information security practices, enterprise digital initiatives are increasingly being emphasized, with information assurance now typically being dealt with by information technology (IT) security specialists. These specialists apply information security to technology (most often some form of computer system). 
IT security specialists are almost always found in any major enterprise/establishment due to the nature and value of the data within larger businesses. They are responsible for keeping all of the technology within the company secure from malicious attacks that often attempt to acquire critical private information or gain control of the internal systems.
There are many specialist roles in Information Security including securing networks and allied infrastructure, securing applications and databases, security testing, information systems auditing, business continuity planning, electronic record discovery, and digital forensics.
Standards.
Information security standards are techniques generally outlined in published materials that attempt to protect the information of a user or organization. This environment includes users themselves, networks, devices, all software, processes, information in storage or transit, applications, services, and systems that can be connected directly or indirectly to networks.
The principal objective is to reduce the risks, including preventing or mitigating attacks. These published materials consist of tools, policies, security concepts, security safeguards, guidelines, risk management approaches, actions, training, best practices, assurance and technologies.
Common information security standards include ISO/IEC 27001 and the NIST Cybersecurity Framework.
Threats.
Information security threats come in many different forms. Some of the most common threats today are software attacks, theft of intellectual property, theft of identity, theft of equipment or information, sabotage, and information extortion. Viruses, worms, phishing attacks, and Trojan horses are a few common examples of software attacks. The theft of intellectual property has also been an extensive issue for many businesses. Identity theft is the attempt to act as someone else usually to obtain that person's personal information or to take advantage of their access to vital information through social engineering. Sabotage usually consists of the destruction of an organization's website in an attempt to cause loss of confidence on the part of its customers. Information extortion consists of theft of a company's property or information as an attempt to receive a payment in exchange for returning the information or property back to its owner, as with ransomware. One of the most functional precautions against these attacks is to conduct periodical user awareness.
Governments, military, corporations, financial institutions, hospitals, non-profit organisations, and private businesses amass a great deal of confidential information about their employees, customers, products, research, and financial status. Should confidential information about a business's customers or finances or new product line fall into the hands of a competitor or hacker, a business and its customers could suffer widespread, irreparable financial loss, as well as damage to the company's reputation. From a business perspective, information security must be balanced against cost; the Gordon-Loeb Model provides a mathematical economic approach for addressing this concern.
For the individual, information security has a significant effect on privacy, which is viewed very differently in various cultures.
History.
Since the early days of communication, diplomats and military commanders understood that it was necessary to provide some mechanism to protect the confidentiality of correspondence and to have some means of detecting tampering. Julius Caesar is credited with the invention of the Caesar cipher c. 50 B.C., which was created in order to prevent his secret messages from being read should a message fall into the wrong hands. However, for the most part protection was achieved through the application of procedural handling controls. Sensitive information was marked up to indicate that it should be protected and transported by trusted persons, guarded and stored in a secure environment or strong box. As postal services expanded, governments created official organizations to intercept, decipher, read, and reseal letters (e.g., the U.K.'s Secret Office, founded in 1653).
In the mid-nineteenth century more complex classification systems were developed to allow governments to manage their information according to the degree of sensitivity. For example, the British Government codified this, to some extent, with the publication of the Official Secrets Act in 1889. Section 1 of the law concerned espionage and unlawful disclosures of information, while Section 2 dealt with breaches of official trust. A public interest defense was soon added to defend disclosures in the interest of the state. A similar law was passed in India in 1889, The Indian Official Secrets Act, which was associated with the British colonial era and used to crack down on newspapers that opposed the Raj's policies. A newer version was passed in 1923 that extended to all matters of confidential or secret information for governance. By the time of the First World War, multi-tier classification systems were used to communicate information to and from various fronts, which encouraged greater use of code making and breaking sections in diplomatic and military headquarters. Encoding became more sophisticated between the wars as machines were employed to scramble and unscramble information.
The establishment of computer security inaugurated the history of information security. The need for such appeared during World War II. The volume of information shared by the Allied countries during the Second World War necessitated formal alignment of classification systems and procedural controls. An arcane range of markings evolved to indicate who could handle documents (usually officers rather than enlisted troops) and where they should be stored as increasingly complex safes and storage facilities were developed. The Enigma Machine, which was employed by the Germans to encrypt the data of warfare and was successfully decrypted by Alan Turing, can be regarded as a striking example of creating and using secured information. Procedures evolved to ensure documents were destroyed properly, and it was the failure to follow these procedures which led to some of the greatest intelligence coups of the war (e.g., the capture of U-570).
Various mainframe computers were connected online during the Cold War to complete more sophisticated tasks, in a communication process easier than mailing magnetic tapes back and forth by computer centers. As such, the Advanced Research Projects Agency (ARPA), of the United States Department of Defense, started researching the feasibility of a networked system of communication to trade information within the United States Armed Forces. In 1968, the ARPANET project was formulated by Larry Roberts, which would later evolve into what is known as the internet.
In 1973, important elements of ARPANET security were found by internet pioneer Robert Metcalfe to have many flaws such as the: "vulnerability of password structure and formats; lack of safety procedures for dial-up connections; and nonexistent user identification and authorizations", aside from the lack of controls and safeguards to keep data safe from unauthorized access. Hackers had effortless access to ARPANET, as phone numbers were known by the public. Due to these problems, coupled with the constant violation of computer security, as well as the exponential increase in the number of hosts and users of the system, "network security" was often alluded to as "network insecurity".
The end of the twentieth century and the early years of the twenty-first century saw rapid advancements in telecommunications, computing hardware and software, and data encryption. The availability of smaller, more powerful, and less expensive computing equipment made electronic data processing within the reach of small business and home users. The establishment of Transfer Control Protocol/Internetwork Protocol (TCP/IP) in the early 1980s enabled different types of computers to communicate. These computers quickly became interconnected through the internet.
The rapid growth and widespread use of electronic data processing and electronic business conducted through the internet, along with numerous occurrences of international terrorism, fueled the need for better methods of protecting the computers and the information they store, process, and transmit. The academic disciplines of computer security and information assurance emerged along with numerous professional organizations, all sharing the common goals of ensuring the security and reliability of information systems.
Security Goals.
CIA triad.
The "CIA triad" of "confidentiality, integrity, and availability" is at the heart of information security. The concept was introduced in the Anderson Report in 1972 and later repeated in "The Protection of Information in Computer Systems." The abbreviation was coined by Steve Lipner around 1986. 
Debate continues about whether or not this triad is sufficient to address rapidly changing technology and business requirements, with recommendations to consider expanding on the intersections between availability and confidentiality, as well as the relationship between security and privacy. Other principles such as "accountability" have sometimes been proposed; it has been pointed out that issues such as non-repudiation do not fit well within the three core concepts.
Confidentiality.
In information security, confidentiality "is the property, that information is not made available or disclosed to unauthorized individuals, entities, or processes." While similar to "privacy," the two words are not interchangeable. Rather, confidentiality is a component of privacy that implements to protect our data from unauthorized viewers. Examples of confidentiality of electronic data being compromised include laptop theft, password theft, or sensitive emails being sent to the incorrect individuals.
Integrity.
In IT security, data integrity means maintaining and assuring the accuracy and completeness of data over its entire lifecycle. This means that data cannot be modified in an unauthorized or undetected manner. This is not the same thing as referential integrity in databases, although it can be viewed as a special case of consistency as understood in the classic ACID model of transaction processing. Information security systems typically incorporate controls to ensure their own integrity, in particular protecting the kernel or core functions against both deliberate and accidental threats. Multi-purpose and multi-user computer systems aim to compartmentalize the data and processing such that no user or process can adversely impact another: the controls may not succeed however, as we see in incidents such as malware infections, hacks, data theft, fraud, and privacy breaches.
More broadly, integrity is an information security principle that involves human/social, process, and commercial integrity, as well as data integrity. As such it touches on aspects such as credibility, consistency, truthfulness, completeness, accuracy, timeliness, and assurance.
Availability.
For any information system to serve its purpose, the information must be available when it is needed. This means the computing systems used to store and process the information, the security controls used to protect it, and the communication channels used to access it must be functioning correctly. High availability systems aim to remain available at all times, preventing service disruptions due to power outages, hardware failures, and system upgrades. Ensuring availability also involves preventing denial-of-service attacks, such as a flood of incoming messages to the target system, essentially forcing it to shut down.
In the realm of information security, availability can often be viewed as one of the most important parts of a successful information security program. Ultimately end-users need to be able to perform job functions; by ensuring availability an organization is able to perform to the standards that an organization's stakeholders expect. This can involve topics such as proxy configurations, outside web access, the ability to access shared drives and the ability to send emails. Executives oftentimes do not understand the technical side of information security and look at availability as an easy fix, but this often requires collaboration from many different organizational teams, such as network operations, development operations, incident response, and policy/change management. A successful information security team involves many different key roles to mesh and align for the "CIA"