Computer security, also known as cyber security or IT security, is the protection of computer systems from the theft and damage to their hardware, software or information, as well as from disruption or misdirection of the services they provide.
Cyber security includes controlling physical access to the hardware, as well as protecting against harm that may come via network access, data and code injection. Also, due to malpractice by operators, whether intentional, accidental, IT security is susceptible to being tricked into deviating from secure procedures through various methods.
The field is of growing importance due to the increasing reliance on computer systems and the Internet, wireless networks such as Bluetooth and Wi-Fi, the growth of "smart" devices, including smartphones, televisions and tiny devices as part of the Internet of Things.
Vulnerabilities and attacks
A vulnerability is a weakness in design, implementation, operation or internal control. As they are discovered many vulnerabilities are documented in the Common Vulnerabilities and Exposures  database.
An exploitable vulnerability is one for which at least one working attack or "exploit" exists. Vulnerabilities are often hunted or exploited with the aid of automated tools.
To secure a computer system, it is important to understand the attacks that can be made against it, and these threats can typically be classified into one of the categories below:
Backdoor
A backdoor in a computer system, a cryptosystem or an algorithm, is any secret method of bypassing normal authentication or security controls. They may exist for a number of reasons, including by original design or from poor configuration. They may have been added by an authorized party to allow some legitimate access, or by an attacker for malicious reasons; but regardless of the motives for their existence, they create a vulnerability.
Denial-of-service attack
Denial of service attacks  are designed to make a machine or network resource unavailable to its intended users. Attackers can deny service to individual victims, such as by deliberately entering a wrong password enough consecutive times to cause the victim account to be locked, or they may overload the capabilities of a machine or network and block all users at once. While a network attack from a single IP address can be blocked by adding a new firewall rule, many forms of Distributed denial of service  attacks are possible, where the attack comes from a large number of points – and defending is much more difficult. Such attacks can originate from the zombie computers of a botnet, but a range of other techniques are possible including reflection and amplification attacks, where innocent systems are fooled into sending traffic to the victim.
Direct-access attacks
An unauthorized user gaining physical access to a computer is most likely able to directly copy data from it. They may also compromise security by making operating system modifications, installing software worms, keyloggers, covert listening devices or using wireless mice. Even when the system is protected by standard security measures, these may be able to be by-passed by booting another operating system or tool from a CD-ROM or other bootable media. Disk encryption and Trusted Platform Module are designed to prevent these attacks.
Eavesdropping
Eavesdropping is the act of surreptitiously listening to a private conversation, typically between hosts on a network. For instance, programs such as Carnivore and NarusInSight have been used by the FBI and NSA to eavesdrop on the systems of internet service providers. Even machines that operate as a closed system  can be eavesdropped upon via monitoring the faint electro-magnetic transmissions generated by the hardware; TEMPEST is a specification by the NSA referring to these attacks.
Spoofing
Spoofing is the act of masquerading as a valid entity through falsification of data, in order to gain access to information or resources that one is otherwise unauthorized to obtain. This can be done in tandem with phishing, and can lead to privilege escalation. There are several types of spoofing, including but not limited to:
Email spoofing, where an attacker forges the sending  address of an email.
IP address spoofing, where an attacker alters the source or destination IP address contained within a network packet.
MAC spoofing, where an attacker modifies the Media Access Control  address of a network interface over which they have control to pose as a valid user on a network.
Biometric spoofing, where an attacker produces a biometric sample that matches to a user other than himself or herself.
Tampering
Tampering describes a malicious modification of products. So-called "Evil Maid" attacks and security services planting of surveillance capability into routers are examples.
Privilege escalation
Privilege escalation describes a situation where an attacker with some level of restricted access is able to, without authorization, elevate their privileges or access level. For example, a standard computer user may be able to fool the system into giving them access to restricted data; or even to "become root" and have full unrestricted access to a system.
Phishing
Phishing is the attempt to acquire sensitive information such as usernames, passwords, and credit card details directly from users. Phishing is typically carried out by email spoofing or instant messaging, and it often directs users to enter details at a fake website whose look and feel are almost identical to the legitimate one. Preying on a victim's trust, phishing can be classified as a form of social engineering.
Clickjacking
Clickjacking, also known as "UI redress attack" or "User Interface redress attack", is a malicious technique in which an attacker tricks a user into clicking on a button or link on another webpage while the user intended to click on the top level page. This is done using multiple transparent or opaque layers. The attacker is basically "hijacking" the clicks meant for the top level page and routing them to some other irrelevant page, most likely owned by someone else. A similar technique can be used to hijack keystrokes. Carefully drafting a combination of stylesheets, iframes, buttons and text boxes, a user can be led into believing that they are typing the password or other information on some authentic webpage while it is being channeled into an invisible frame controlled by the attacker.
Social engineering
Social engineering aims to convince a user to disclose secrets such as passwords, card numbers, etc. by, for example, impersonating a bank, a contractor, or a customer.
A common scam involves fake CEO emails sent to accounting and finance departments. In early 2016, the FBI reported that the scam has cost US businesses more than $2bn in about two years.
In May 2016, the Milwaukee Bucks NBA team was the victim of this type of cyber scam with a perpetrator impersonating the team's president Peter Feigin, resulting in the handover of all the team's employees' 2015 W-2 tax forms.
Information security culture
Employee behavior can have a big impact on information security in organizations. Cultural concepts can help different segments of the organization work effectively or work against effectiveness towards information security within an organization.″Exploring the Relationship between Organizational Culture and Information Security Culture″ provides the following definition of information security culture: ″ISC is the totality of patterns of behavior in an organization that contribute to the protection of information of all kinds.″
Andersson and Reimers  found that employees often do not see themselves as part of the organization Information Security "effort" and often take actions that ignore organizational Information Security best interests. Research shows Information security culture needs to be improved continuously. In ″Information Security Culture from Analysis to Change″, authors commented, ″It′s a never ending process, a cycle of evaluation and change or maintenance.″ To manage the information security culture, five steps should be taken: Pre-evaluation, strategic planning, operative planning, implementation, and post-evaluation.
Pre-Evaluation: to identify the awareness of information security within employees and to analyze the current security policy.
Strategic Planning: to come up with a better awareness program, clear targets need to be set. Clustering people is helpful to achieve it.
Operative Planning: a good security culture can be established based on internal communication, management-buy-in, and security awareness and a training program. Web sites and apps that accept or store credit card numbers, brokerage accounts, and bank account information are also prominent hacking targets, because of the potential for immediate financial gain from transferring money, making purchases, or selling the information on the black market. In-store payment systems and ATMs have also been tampered with in order to gather customer account data and PINs.
Utilities and industrial equipment
Computers control functions at many utilities, including coordination of telecommunications, the power grid, nuclear power plants, and valve opening and closing in water and gas networks. The Internet is a potential attack vector for such machines if connected, but the Stuxnet worm demonstrated that even equipment controlled by computers not connected to the Internet can be vulnerable. In 2014, the Computer Emergency Readiness Team, a division of the Department of Homeland Security, investigated 79 hacking incidents at energy companies. Vulnerabilities in smart meters  can cause problems with billing fraud.
Aviation
The aviation industry is very reliant on a series of complex system which could be attacked. A simple power outage at one airport can cause repercussions worldwide, much of the system relies on radio transmissions which could be disrupted, and controlling aircraft over oceans is especially dangerous because radar surveillance only extends 175 to 225 miles offshore. There is also potential for attack from within an aircraft.
In Europe, with the  and NewPENS, and in the US with the NextGen program, air navigation service providers are moving to create their own dedicated networks.
The consequences of a successful attack range from loss of confidentiality to loss of system integrity, air traffic control outages, loss of aircraft, and even loss of life.
Consumer devices
Desktop computers and laptops are commonly targeted to gather passwords or financial account information, or to construct a botnet to attack another target. Smart phones, tablet computers, smart watches, and other mobile devices such as quantified self devices like activity trackers have sensors such as cameras, microphones, GPS receivers, compasses, and accelerometers which could be exploited, and may collect personal information, including sensitive health information. Wifi, Bluetooth, and cell phone networks on any of these devices could be used as attack vectors, and sensors might be remotely activated after a successful breach.
The increasing number of home automation devices such as the Nest thermostat are also potential targets. Staples, and Target Corporation. Medical records have been targeted for use in general identify theft, health insurance fraud, and impersonating patients to obtain prescription drugs for recreational purposes or resale. Although cyber threats continue to increase, 62% of all organizations did not increase security training for their business in 2015.
Not all attacks are financially motivated however; for example security firm HBGary Federal suffered a serious series of attacks in 2011 from hacktivist group Anonymous in retaliation for the firm's CEO claiming to have infiltrated their group, and in the Sony Pictures attack of 2014 the motive appears to have been to embarrass with data leaks, and cripple the company by wiping workstations and servers.
Automobiles
Vehicles are increasingly computerized, with engine timing, cruise control, anti-lock brakes, seat belt tensioners, door locks, airbags and advanced driver-assistance systems on many models. Additionally, connected cars may use Wif-Fi and bluetooth to communicate with onboard consumer devices and the cell phone network. Simple examples of risk include a malicious compact disc being used as an attack vector, and the car's onboard microphones being used for eavesdropping. However, if access is gained to a car's internal controller area network, the danger is much greater – and in a widely publicised 2015 test, hackers remotely carjacked a vehicle from 10 miles away and drove it into a ditch.
Manufacturers are reacting in a number of ways, with Tesla in 2016 pushing out some security fixes "over the air" into its cars' computer systems.
In the area of autonomous vehicles, in September 2016 the United States Department of Transportation announced some initial safety standards, and called for states to come up with uniform policies.
Government
Government and military computer systems are commonly attacked by activists and foreign powers. Local and regional government infrastructure such as traffic light controls, police and intelligence agency communications, personnel records, student records, and financial systems are also potential targets as they are now all largely computerized. Passports and government ID cards that control access to facilities which use RFID can be vulnerable to cloning.
Internet of things and physical vulnerabilities
The Internet of things  is the network of physical objects such as devices, vehicles, and buildings that are embedded with electronics, software, sensors, and network connectivity that enables them to collect and exchange data – and concerns have been raised that this is being developed without appropriate consideration of the security challenges involved.
While the IoT creates opportunities for more direct integration of the physical world into computer-based systems,
it also provides opportunities for misuse. In particular, as the Internet of Things spreads widely, cyber attacks are likely to become an increasingly physical  threat. If a front door's lock is connected to the Internet, and can be locked/unlocked from a phone, then a criminal could enter the home at the press of a button from a stolen or hacked phone. People could stand to lose much more than their credit card numbers in a world controlled by IoT-enabled devices. Thieves have also used electronic means to circumvent non-Internet-connected hotel door locks.
Medical systems
Medical devices have either been successfully attacked or had potentially deadly vulnerabilities demonstrated, including both in-hospital diagnostic equipment and implanted devices including pacemakers and insulin pumps. There are many reports of hospitals and hospital organizations getting hacked, including ransomware attacks, Windows XP exploits, viruses, and data breaches of sensitive data stored on hospital servers. On 28 December 2016 the US Food and Drug Administration released its recommendations for how medical device manufacturers should maintain the security of Internet-connected devices – but no structure for enforcement.
Impact of security breaches
Serious financial damage has been caused by security breaches, but because there is no standard model for estimating the cost of an incident, the only data available is that which is made public by the organizations involved. "Several computer security consulting firms produce estimates of total worldwide losses attributable to virus and worm attacks and to hostile digital acts in general. The 2003 loss estimates by these firms range from $13 billion  to $226 billion . The reliability of these estimates is often challenged; the underlying methodology is basically anecdotal." Security breaches continue to cost businesses billions of dollars but a survey revealed that 66% of security staffs do not believe senior leadership takes cyber precautions as a strategic priority.
Attacker motivation
As with physical security, the motivations for breaches of computer security vary between attackers. Some are thrill-seekers or vandals, some are activists, others are criminals looking for financial gain. State-sponsored attackers are now common and well resourced, but started with amateurs such as Markus Hess who hacked for the KGB, as recounted by Clifford Stoll, in The Cuckoo's Egg. Thieves are often seen as a type of an attacker that seek out financial or other valued gain. Several attackers are motivated by manipulating naive user system towards launching larger overarching denial of service attacks, and serve as Zombies in a large Botnet. Attack motivations for hackers in the United States has shown to be the common place, as its share fell from 58% to 37% in 2009. There are also defensive attackers that utilize conventional law enforcement. For example, in January 2000, Conxion returned an attack on source servers after its WTO servers were attacked by a DDOS.
Some common countermeasures are listed in the following sections:
Security by design
Security by design, or alternately secure by design, means that the software has been designed from the ground up to be secure. In this case, security is considered as a main feature.
Some of the techniques in this approach include:
The principle of least privilege, where each part of the system has only the privileges that are needed for its function. That way even if an attacker gains access to that part, they have only limited access to the whole system.
Automated theorem proving to prove the correctness of crucial software subsystems.
Code reviews and unit testing, approaches to make modules more secure where formal correctness proofs are not possible.
Defense in depth, where the design is such that more than one subsystem needs to be violated to compromise the integrity of the system and the information it holds.
Default secure settings, and design to "fail secure" rather than "fail insecure" . Ideally, a secure system should require a deliberate, conscious, knowledgeable and free decision on the part of legitimate authorities in order to make it insecure.
Audit trails tracking system activity, so that when a security breach occurs, the mechanism and extent of the breach can be determined. Storing audit trails remotely, where they can only be appended to, can keep intruders from covering their tracks.
Full disclosure of all vulnerabilities, to ensure that the "window of vulnerability" is kept as short as possible when bugs are discovered.
Security architecture
The Open Security Architecture organization defines IT security architecture as "the design artifacts that describe how the security controls  are positioned, and how they relate to the overall information technology architecture. These controls serve the purpose to maintain the system's quality attributes: confidentiality, integrity, availability, accountability and assurance services".
Techopedia defines security architecture as "a unified security design that addresses the necessities and potential risks involved in a certain scenario or environment. It also specifies when and where to apply security controls. The design process is generally reproducible." The key attributes of security architecture are:
the relationship of different components and how they depend on each other.
the determination of controls based on risk assessment, good practice, finances, and legal matters.
the standardization of controls.
Security measures
A state of computer "security" is the conceptual ideal, attained by the use of the three processes: threat prevention, detection, and response. These processes are based on various policies and system components, which include the following:
User account access controls and cryptography can protect systems files and data, respectively.
Firewalls are by far the most common prevention systems from a network security perspective as they can  shield access to internal network services, and block certain kinds of attacks through packet filtering. Firewalls can be both hardware- or software-based.
Intrusion Detection System  products are designed to detect network attacks in-progress and assist in post-attack forensics, while audit trails and logs serve a similar function for individual systems.
"Response" is necessarily defined by the assessed security requirements of an individual system and may cover the range from simple upgrade of protections to notification of legal authorities, counter-attacks, and the like. In some special cases, a complete destruction of the compromised system is favored, as it may happen that not all the compromised resources are detected.
Today, computer security comprises mainly "preventive" measures, like firewalls or an exit procedure. A firewall can be defined as a way of filtering network data between a host or a network and another network, such as the Internet, and can be implemented as software running on the machine, hooking into the network stack  to provide real time filtering and blocking. Another implementation is a so-called "physical firewall", which consists of a separate machine filtering network traffic. Firewalls are common amongst machines that are permanently connected to the Internet.
Some organizations are turning to big data platforms, such as Apache Hadoop, to extend data accessibility and machine learning to detect advanced persistent threats.
However, relatively few organisations maintain computer systems with effective detection systems, and fewer still have organised response mechanisms in place. As result, as Reuters points out: "Companies for the first time report they are losing more through electronic theft of data than physical stealing of assets". The primary obstacle to effective eradication of cyber crime could be traced to excessive reliance on firewalls and other automated "detection" systems. Yet it is basic evidence gathering by using packet capture appliances that puts criminals behind bars.
Vulnerability management
Vulnerability management is the cycle of identifying, and remediating or mitigating vulnerabilities, especially in software and firmware. Vulnerability management is integral to computer security and network security.
Vulnerabilities can be discovered with a vulnerability scanner, which analyzes a computer system in search of known vulnerabilities, such as open ports, insecure software configuration, and susceptibility to malware
Beyond vulnerability scanning, many organisations contract outside security auditors to run regular penetration tests against their systems to identify vulnerabilities. In some sectors this is a contractual requirement.
Reducing vulnerabilities
While formal verification of the correctness of computer systems is possible, it is not yet common. Operating systems formally verified include seL4, and SYSGO's PikeOS – but these make up a very small percentage of the market.
Cryptography properly implemented is now virtually impossible to directly break. Breaking them requires some non-cryptographic input, such as a stolen key, stolen plaintext, or some other extra cryptanalytic information.
Two factor authentication is a method for mitigating unauthorized access to a system or sensitive information. It requires "something you know"; a password or PIN, and "something you have"; a card, dongle, cellphone, or other piece of hardware. This increases security as an unauthorized person needs both of these to gain access.
Social engineering and direct computer access  attacks can only be prevented by non-computer means, which can be difficult to enforce, relative to the sensitivity of the information. Training is often involved to help mitigate this risk, but even in a highly disciplined environments, social engineering attacks can still be difficult to foresee and prevent.
Enoculation, derived from Inoculation theory, seeks to prevent social engineering and other fraudulent tricks or traps by instilling a resistance to persuasion attempts through exposure to similar or related attempts.
It is possible to reduce an attacker's chances by keeping systems up to date with security patches and updates, using a security scanner or/and hiring competent people responsible for security. The effects of data loss/damage can be reduced by careful backing up and insurance.
Hardware protection mechanisms
While hardware may be a source of insecurity, such as with microchip vulnerabilities maliciously introduced during the manufacturing process, hardware-based or assisted computer security also offers an alternative to software-only computer security. Using devices and methods such as dongles, trusted platform modules, intrusion-aware cases, drive locks, disabling USB ports, and mobile-enabled access may be considered more secure due to the physical access  required in order to be compromised. Each of these is covered in more detail below.
USB dongles are typically used in software licensing schemes to unlock software capabilities, but they can also be seen as a way to prevent unauthorized access to a computer or other device's software. The dongle, or key, essentially creates a secure encrypted tunnel between the software application and the key. The principle is that an encryption scheme on the dongle, such as Advanced Encryption Standard  provides a stronger measure of security, since it is harder to hack and replicate the dongle than to simply copy the native software to another machine and use it. Another security application for dongles is to use them for accessing web-based content such as cloud software or Virtual Private Networks . In addition, a USB dongle can be configured to lock or unlock a computer.
Trusted platform modules  secure devices by integrating cryptographic capabilities onto access devices, through the use of microprocessors, or so-called computers-on-a-chip. TPMs used in conjunction with server-side software offer a way to detect and authenticate hardware devices, preventing unauthorized network and data access.
Computer case intrusion detection refers to a push-button switch which is triggered when a computer case is opened. The firmware or BIOS is programmed to show an alert to the operator when the computer is booted up the next time.
Drive locks are essentially software tools to encrypt hard drives, making them inaccessible to thieves. Tools exist specifically for encrypting external drives as well.
Disabling USB ports is a security option for preventing unauthorized and malicious access to an otherwise secure computer. Infected USB dongles connected to a network from a computer inside the firewall are considered by the magazine Network World as the most common hardware threat facing computer networks.
Mobile-enabled access devices are growing in popularity due to the ubiquitous nature of cell phones. Built-in capabilities such as Bluetooth, the newer Bluetooth low energy, Near field communication  on non-iOS devices and biometric validation such as thumb print readers, as well as QR code reader software designed for mobile devices, offer new, secure ways for mobile phones to connect to access control systems. These control systems provide computer security and can also be used for controlling access to secure buildings.
Secure operating systems
One use of the term "computer security" refers to technology that is used to implement secure operating systems. In the 1980s the United States Department of Defense  used the "Orange Book" standards, but the current international standard ISO/IEC 15408, "Common Criteria" defines a number of progressively more stringent Evaluation Assurance Levels. Many common operating systems meet the EAL4 standard of being "Methodically Designed, Tested and Reviewed", but the formal verification required for the highest levels means that they are uncommon. An example of an EAL6  system is Integrity-178B, which is used in the Airbus A380
and several military jets.
Secure coding
In software engineering, secure coding aims to guard against the accidental introduction of security vulnerabilities. It is also possible to create software designed from the ground up to be secure. Such systems are "secure by design". Beyond this, formal verification aims to prove the correctness of the algorithms underlying a system;
important for cryptographic protocols for example.
Capabilities and access control lists
Within computer systems, two of many security models capable of enforcing privilege separation are access control lists  and capability-based security. Using ACLs to confine programs has been proven to be insecure in many situations, such as if the host computer can be tricked into indirectly allowing restricted file access, an issue known as the confused deputy problem. It has also been shown that the promise of ACLs of giving access to an object to only one person can never be guaranteed in practice. Both of these problems are resolved by capabilities. This does not mean practical flaws exist in all ACL-based systems, but only that the designers of certain utilities must take responsibility to ensure that they do not introduce flaws.
Capabilities have been mostly restricted to research operating systems, while commercial OSs still use ACLs. Capabilities can, however, also be implemented at the language level, leading to a style of programming that is essentially a refinement of standard object-oriented design. An open source project in the area is the E language.
The most secure computers are those not connected to the Internet and shielded from any interference. In the real world, the most secure systems are operating systems where security is not an add-on.
Response to breaches
Responding forcefully to attempted security breaches  is often very difficult for a variety of reasons:
Identifying attackers is difficult, as they are often in a different jurisdiction to the systems they attempt to breach, and operate through proxies, temporary anonymous dial-up accounts, wireless connections, and other anonymising procedures which make backtracing difficult and are often located in yet another jurisdiction. If they successfully breach security, they are often able to delete logs to cover their tracks.
The sheer number of attempted attacks is so large that organisations cannot spend time pursuing each attacker  connection will be attacked at least several times per day, so more attractive targets could be presumed to see many more). Note however, that most of the sheer bulk of these attacks are made by automated vulnerability scanners and computer worms.
Law enforcement officers are often unfamiliar with information technology, and so lack the skills and interest in pursuing attackers. There are also budgetary constraints. It has been argued that the high cost of technology, such as DNA testing, and improved forensics mean less money for other kinds of law enforcement, so the overall rate of criminals not getting dealt with goes up as the cost of the technology increases. In addition, the identification of attackers across a network may require logs from various points in the network and in many countries, the release of these records to law enforcement  requires a search warrant and, depending on the circumstances, the legal proceedings required can be drawn out to the point where the records are either regularly destroyed, or the information is no longer relevant.
Notable attacks and breaches
Some illustrative examples of different types of computer security breaches are given below.
Robert Morris and the first computer worm
In 1988, only 60,000 computers were connected to the Internet, and most were mainframes, minicomputers and professional workstations. On 2 November 1988, many started to slow down, because they were running a malicious code that demanded processor time and that spread itself to other computers – the first internet "computer worm". The software was traced back to 23-year-old Cornell University graduate student Robert Tappan Morris, Jr. who said 'he wanted to count how many machines were connected to the Internet'.
TJX customer credit card details
In early 2007, American apparel and home goods company TJX announced that it was the victim of an unauthorized computer systems intrusion and that the hackers had accessed a system that stored data on credit card, debit card, check, and merchandise return transactions.
Stuxnet attack
The computer worm known as Stuxnet reportedly ruined almost one-fifth of Iran's nuclear centrifuges by disrupting industrial programmable logic controllers  in a targeted attack generally believed to have been launched by Israel and the United States – although neither has publicly admitted this.
Global surveillance disclosures
In early 2013, documents provided by Edward Snowden were published by The Washington Post and The Guardian exposing the massive scale of NSA global surveillance. It was also revealed that the NSA had deliberately inserted a backdoor in a NIST standard for encryption and tapped the links between Google's data centres.
Target and Home Depot breaches
In 2013 and 2014, a Russian/Ukrainian hacking ring known as "Rescator" broke into Target Corporation computers in 2013, stealing roughly 40 million credit cards, and then Home Depot computers in 2014, stealing between 53 and 56 million credit card numbers. Warnings were delivered at both corporations, but ignored; physical security breaches using self checkout machines are believed to have played a large role. "The malware utilized is absolutely unsophisticated and uninteresting," says Jim Walter, director of threat intelligence operations at security technology company McAfee – meaning that the heists could have easily been stopped by existing antivirus software had administrators responded to the warnings. The size of the thefts has resulted in major attention from state and Federal United States authorities and the investigation is ongoing.
Office of Personnel Management data breach
In April 2015, the Office of Personnel Management discovered it had been hacked more than a year earlier in a data breach, resulting in the theft of approximately 21.5 million personnel records handled by the office. The Office of Personnel Management hack has been described by federal officials as among the largest breaches of government data in the history of the United States. Data targeted in the breach included personally identifiable information such as Social Security Numbers, names, dates and places of birth, addresses, and fingerprints of current and former government employees as well as anyone who had undergone a government background check. It is believed the hack was perpetrated by Chinese hackers but the motivation remains unclear.
Ashley Madison breach
In July 2015, a hacker group known as "The Impact Team" successfully breached the extramarital relationship website Ashley Madison. The group claimed that they had taken not only company data but user data as well. After the breach, The Impact Team dumped emails from the company's CEO, to prove their point, and threatened to dump customer data unless the website was taken down permanently. With this initial data release, the group stated "Avid Life Media has been instructed to take Ashley Madison and Established Men offline permanently in all forms, or we will release all customer records, including profiles with all the customers' secret sexual fantasies and matching credit card transactions, real names and addresses, and employee documents and emails. The other websites may stay online." When Avid Life Media, the parent company that created the Ashley Madison website, did not take the site offline, The Impact Group released two more compressed files, one 9.7GB and the second 20GB. After the second data dump, Avid Life Media CEO Noel Biderman resigned, but the website remained functional.
Legal issues and global regulation
Conflict of laws in cyberspace has become a major cause of concern for computer security community. Some of the main challenges and complaints about the antivirus industry are the lack of global web regulations, a global base of common rules to judge, and eventually punish, cyber crimes and cyber criminals. There is no global cyber law and cyber security treaty that can be invoked for enforcing global cyber security issues.
International legal issues of cyber attacks are complicated in nature. Even if an antivirus firm locates the cybercriminal behind the creation of a particular virus or piece of malware or form of cyber attack, often the local authorities cannot take action due to lack of laws under which to prosecute. Authorship attribution for cyber crimes and cyber attacks is a major problem for all law enforcement agencies.
" switch from one country to another, from one jurisdiction to another – moving around the world, using the fact that we don't have the capability to globally police operations like this. So the Internet is as if someone  given free plane tickets to all the online criminals of the world."
The question of whether the government should intervene or not in the regulation of the cyberspace is a very polemical one. Indeed, for as long as it has existed and by definition, the cyberspace is a virtual space free of any government intervention. Where everyone agrees that an improvement on cyber security is more than vital, is the government the best actor to solve this issue?
Many government officials and experts think that the government should step in and that there is a crucial need for regulation, mainly due to the failure of the private sector to solve efficiently the cybersecurity problem. R. Clarke said during a panel discussion at the RSA Security Conference in San Francisco, he believes that the "industry only responds when you threaten regulation. If the industry doesn't respond, you have to follow through."
On the other hand, executives from the private sector agree that improvements are necessary, but think that the government intervention would affect their ability to innovate efficiently.
International actions
Many different teams and organisations exist, including:
The Forum of Incident Response and Security Teams  is the global association of CSIRTs. The US-CERT, AT&T, Apple, Cisco, McAfee, Microsoft are all members of this international team.
The Council of Europe helps protect societies worldwide from the threat of cybercrime through the Convention on Cybercrime.
The purpose of the Messaging Anti-Abuse Working Group  is to bring the messaging industry together to work collaboratively and to successfully address the various forms of messaging abuse, such as spam, viruses, denial-of-service attacks and other messaging exploitations. France Telecom, Facebook, AT&T, Apple, Cisco, Sprint are some of the members of the MAAWG.
ENISA : The European Network and Information Security Agency  is an agency of the European Union with the objective to improve network and information security in the European Union.
Europe
CSIRTs in Europe collaborate in the TERENA task force TF-CSIRT. TERENA's Trusted Introducer service provides an accreditation and certification scheme for CSIRTs in Europe. A full list of known CSIRTs in Europe is available from the Trusted Introducer website.
National actions
Computer emergency response teams
Most countries have their own computer emergency response team to protect network security.
Canada
On 3 October 2010, Public Safety Canada unveiled Canada's Cyber Security Strategy, following a Speech from the Throne commitment to boost the security of Canadian cyberspace. Three main pillars define the strategy: securing government systems, partnering to secure vital cyber systems outside the federal government, and helping Canadians to be secure online. The Cyber Incident Management Framework for Canada outlines these responsibilities, and provides a plan for coordinated response between government and other partners in the event of a cyber incident. The Action Plan 2010–2015 for Canada's Cyber Security Strategy outlines the ongoing implementation of the strategy.
Public Safety Canada's Canadian Cyber Incident Response Centre  is responsible for mitigating and responding to threats to Canada's critical infrastructure and cyber systems. The CCIRC provides support to mitigate cyber threats, technical support to respond and recover from targeted cyber attacks, and provides online tools for members of Canada's critical infrastructure sectors. The CCIRC posts regular cyber security bulletins on the Public Safety Canada website. The CCIRC also operates an online reporting tool where individuals and organizations can report a cyber incident. Canada's Cyber Security Strategy is part of a larger, integrated approach to critical infrastructure protection, and functions as a counterpart document to the National Strategy and Action Plan for Critical Infrastructure. On 4 February 2014, the Government of Canada launched the Cyber Security Cooperation Program. The program is a $1.5 million five-year initiative aimed at improving Canada's cyber systems through grants and contributions to projects in support of this objective. Public Safety Canada aims to begin an evaluation of Canada's Cyber Security Strategy in early 2015.
China
China's Central Leading Group for Internet Security and Informatization  was established on 27 February 2014. This Leading Small Group  of the Communist Party of China is headed by General Secretary Xi Jinping himself and is staffed with relevant Party and state decision-makers. The LSG was created to overcome the incoherent policies and overlapping responsibilities that characterized China's former cyberspace decision-making mechanisms. The LSG oversees policy-making in the economic, political, cultural, social and military fields as they relate to network security and IT strategy. This LSG also coordinates major policy initiatives in the international arena that promote norms and standards favored by the Chinese government and that emphasize the principle of national sovereignty in cyberspace.
Germany
Berlin starts National Cyber Defense Initiative:
On 16 June 2011, the German Minister for Home Affairs, officially opened the new German NCAZ  Nationales Cyber-Abwehrzentrum located in Bonn. The NCAZ closely cooperates with BSI  Bundesamt für Sicherheit in der Informationstechnik, BKA  Bundeskriminalamt, BND  Bundesnachrichtendienst, MAD  Amt für den Militärischen Abschirmdienst and other national organisations in Germany taking care of national security aspects. According to the Minister the primary task of the new organization founded on 23 February 2011, is to detect and prevent attacks against the national infrastructure and mentioned incidents like Stuxnet.
India
Some provisions for cyber security have been incorporated into rules framed under the Information Technology Act 2000.
The National Cyber Security Policy 2013 is a policy framework by Ministry of Electronics and Information Technology  which aims to protect the public and private infrastructure from cyber attacks, and safeguard "information, such as personal information, financial and banking information and sovereign data".
The Indian Companies Act 2013 has also introduced cyber law and cyber security obligations on the part of Indian directors.
Portugal
O  em Portugal promove a utilização do ciberespaço de uma forma livre, confiável e segura, através da melhoria contínua da cibersegurança nacional e da cooperação internacional.
— Cyber Security Services,  is a Portuguese company specialized in cyber security,
Pakistan
Cyber-crime has risen rapidly in Pakistan. There are about 34 million Internet users with 133.4 million mobile subscribers in Pakistan. According to Cyber Crime Unit, a branch of Federal Investigation Agency, only 62 cases were reported to the unit in 2007, 287 cases in 2008, ratio dropped in 2009 but in 2010, more than 312 cases were registered. However, there are many unreported incidents of cyber-crime.
"Pakistan's Cyber Crime Bill 2007", the first pertinent law, focuses on electronic crimes, for example cyber-terrorism, criminal access, electronic system fraud, electronic forgery, and misuse of encryption. However, certain private firms are also working in cohesion with the government to improve cyber security and curb cyber attacks.
South Korea
Following cyber attacks in the first half of 2013, when the government, news media, television station, and bank websites were compromised, the national government committed to the training of 5,000 new cybersecurity experts by 2017. The South Korean government blamed its northern counterpart for these attacks, as well as incidents that occurred in 2009, 2011, and 2012, but Pyongyang denies the accusations.
United States
Legislation
The 1986, more commonly known as the Computer Fraud and Abuse Act is the key legislation. It prohibits unauthorized access or damage of "protected computers" as defined in .
Although various other measures have been proposed, such as the "Cybersecurity Act of 2010 – S. 773" in 2009, the "International Cybercrime Reporting and Cooperation Act – H.R.4962" and "Protecting Cyberspace as a National Asset Act of 2010 – S.3480" in 2010 – none of these has succeeded.
Executive order 13636 Improving Critical Infrastructure Cybersecurity was signed 12 February 2013.
Agencies
The Department of Homeland Security has a dedicated division responsible for the response system, risk management program and requirements for cybersecurity in the United States called the National Cyber Security Division. The National Cybersecurity and Communications Integration Center brings together government organizations responsible for protecting computer networks and networked infrastructure.
The third priority of the Federal Bureau of Investigation  is to: "Protect the United States against cyber-based attacks and high-technology crimes", and they, along with the National White Collar Crime Center, and the Bureau of Justice Assistance  are part of the multi-agency task force, The Internet Crime Complaint Center, also known as IC3.
In addition to its own specific duties, the FBI participates alongside non-profit organizations such as InfraGard.
In the criminal division of the United States Department of Justice operates a section called the Computer Crime and Intellectual Property Section. The CCIPS is in charge of investigating computer crime and intellectual property crime and is specialized in the search and seizure of digital evidence in computers and networks.
The United States Cyber Command, also known as USCYBERCOM, is tasked with the defense of specified Department of Defense information networks and "ensure US/Allied freedom of action in cyberspace and deny the same to our adversaries." It has no role in the protection of civilian networks.
The U.S. Federal Communications Commission's role in cybersecurity is to strengthen the protection of critical communications infrastructure, to assist in maintaining the reliability of networks during disasters, to aid in swift recovery after, and to ensure that first responders have access to effective communications services.
The Food and Drug Administration has issued guidance for medical devices, and the National Highway Traffic Safety Administration is concerned with automotive cybersecurity. After being criticized by the Government Accountability Office, and following successful attacks on airports and claimed attacks on airplanes, the Federal Aviation Administration has devoted funding to securing systems on board the planes of private manufacturers, and the Aircraft Communications Addressing and Reporting System. Concerns have also been raised about the future Next Generation Air Transportation System.
Computer emergency readiness team
"Computer emergency response team" is a name given to expert groups that handle computer security incidents.
In the US, two distinct organization exist, although they do work closely together.
US-CERT: part of the National Cyber Security Division of the United States Department of Homeland Security.
CERT/CC: created by the Defense Advanced Research Projects Agency  and run by the Software Engineering Institute .
Modern warfare
There is growing concern that cyberspace will become the next theater of warfare. As Mark Clayton from the Christian Science Monitor described in an article titled "The New Cyber Arms Race":
In the future, wars will not just be fought by soldiers with guns or with planes that drop bombs. They will also be fought with the click of a mouse a half a world away that unleashes carefully weaponized computer programs that disrupt or destroy critical industries like utilities, transportation, communications, and energy. Such attacks could also disable military networks that control the movement of troops, the path of jet fighters, the command and control of warships.
This has led to new terms such as cyberwarfare and cyberterrorism. The United States Cyber Command was created in 2009 and many other countries have similar forces.
Job market
Cybersecurity is a fast-growing field of IT concerned with reducing organizations' risk of hack or data breach. According to research from the Enterprise Strategy Group, 46% of organizations say that they have a "problematic shortage" of cybersecurity skills in 2016, up from 28% in 2015. Commercial, government and non-governmental organizations all employ cybersecurity professionals. The fastest increases in demand for cybersecurity workers are in industries managing increasing volumes of consumer data such as finance, health care, and retail. However, the use of the term "cybersecurity" is more prevalent in government job descriptions.
Cybersecurity is increasingly affected by Department of Defense  Dir. 8570.1M and 8140. Dir. 8570.1 was enacted in 2004 and mandates specific industry credentials for certain  . Andersson and Reimers found that CIS/IT students were keenly aware if their instructors had them. For example, certain certifications DOD 8570.1M are the only commercial certifications that the Department of Defense will accept towards meeting their Information Assurance hiring requirements.
Typical cyber security job titles and descriptions include:
Security analyst

Security engineer:

Security architect:

Security administrator:

Chief Information Security Officer :

Chief Security Officer :

Security Consultant/Specialist/Intelligence:

Student programs are also available to people interested in beginning a career in cybersecurity. Meanwhile, a flexible and effective option for information security professionals of all experience levels to keep studying is online security training, including webcasts.
Terminology
The following terms used with regards to engineering secure systems are explained below.
Access authorization restricts access to a computer to the group of users through the use of authentication systems. These systems can protect either the whole computer – such as through an interactive login screen – or individual services, such as an FTP server. There are many methods for identifying and authenticating users, such as passwords, identification cards, and, more recently, smart cards and biometric systems.
Anti-virus software consists of computer programs that attempt to identify, thwart and eliminate computer viruses and other malicious software .
Applications are executable code, so general practice is to disallow users the power to install them; to install only those which are known to be reputable – and to reduce the attack surface by installing as few as possible. They are typically run with least privilege, with a robust process in place to identify, test and install any released security patches or updates for them.
Authentication techniques can be used to ensure that communication end-points are who they say they are.]
Automated theorem proving and other verification tools can enable critical algorithms and code used in secure systems to be mathematically proven to meet their specifications.
Backups are one or more copies kept of important computer files. Typically multiple copies,, will be kept in different location away from the original, so that they are secure from damage if the original location has its security breached by an attacker, or is destroyed or damaged by natural disasters.
Capability and access control list techniques can be used to ensure privilege separation and mandatory access control. This section discusses their use.
Chain of trust techniques can be used to attempt to ensure that all software loaded has been certified as authentic by the system's designers.
Confidentiality is the nondisclosure of information except to another authorized person.
Cryptographic techniques can be used to defend data in transit between systems, reducing the probability that data exchanged between systems can be intercepted or modified.
Cyberwarfare is an internet-based conflict that involves politically motivated attacks on information and information systems. Such attacks can, for example, disable official websites and networks, disrupt or disable essential services, steal or alter classified data, and cripple financial systems.
Data integrity is the accuracy and consistency of stored data, indicated by an absence of any alteration in data between two updates of a data record.
Encryption is used to protect the message from the eyes of others. Cryptographically secure ciphers are designed to make any practical attempt of breaking infeasible. Symmetric-key ciphers are suitable for bulk encryption using shared keys, and public-key encryption using digital certificates can provide a practical solution for the problem of securely communicating when no key is shared in advance.
Endpoint security software helps networks to prevent exfiltration  and virus infection at network entry points made vulnerable by the prevalence of potentially infected portable computing devices, such as laptops and mobile devices, and external storage devices, such as USB drives.
Firewalls serve as a gatekeeper system between networks, allowing only traffic that matches defined rules. They often include detailed logging, and may include intrusion detection and intrusion prevention features. They are near-universal between company local area networks and the Internet, but can also be used internally to impose traffic rules between networks if network segmentation is configured.
Honey pots are computers that are intentionally left vulnerable to attack by crackers. They can be used to catch crackers and to identify their techniques.
Intrusion-detection systems can scan a network for people that are on the network but who should not be there or are doing things that they should not be doing, for example trying a lot of passwords to gain access to the network.
A microkernel is an approach to operating system design which has only the near-minimum amount of code running at the most privileged level – and runs other elements of the operating system such as device drivers, protocol stacks and file systems, in the safer, less privileged user space.
Pinging. The standard "ping" application can be used to test if an IP address is in use. If it is, attackers may then try a port scan to detect which services are exposed.
A port scan is used to probe an IP address for open ports, and hence identify network services running there.
Social engineering is the use of deception to manipulate individuals to breach security.