ICDL Cyber Security (ICDL) key terms

The principle that information is only seen by people who are authorised to see it. It is protected by controls such as passwords, encryption and access permissions.

The principle that data stays complete and unaltered unless a change is made deliberately by someone authorised. It guards against accidental or malicious modification of files and records.

The principle that systems and data are reachable and usable by authorised people when they are needed. Backups, maintenance and protection against attacks all support it.

The process of proving that a person or system is who they claim to be. It usually relies on something you know, something you have, or something you are.

The process of deciding what an authenticated user is allowed to do. It grants or denies access to specific files, folders, functions or services after identity has been confirmed.

A general name for software written to cause harm, steal data or take control of a device. Viruses, worms, trojans, spyware and ransomware are all types of it.

A piece of malicious code that attaches itself to a legitimate file or program and spreads when that item is opened or run. It often needs a user action to activate.

Malicious software that copies itself and spreads across networks without any action from the user. It often exploits weaknesses in unpatched systems and can spread very quickly.

Malicious software disguised as something useful or legitimate, such as a free tool or attachment. Once installed it can open a back door or download further threats.

Malicious software that locks or encrypts a victim's files and demands payment to restore access. Regular offline backups are the most reliable defence against it.

Software that secretly monitors a user's activity, collecting information such as browsing habits, keystrokes or login details and sending it to a third party.

A tool, either hardware or software, that records every keystroke a user types. It is used to capture passwords and other sensitive text without the user's knowledge.

A scam that uses fake messages, often email, to trick people into revealing passwords or financial details, or into opening a malicious attachment or link.

A targeted form of phishing aimed at a specific person or organisation, using personal details to make the message convincing. It is harder to spot than bulk phishing.

Phishing carried out through text messages or messaging apps rather than email. The message usually contains a link or a request to reply with sensitive information.

Manipulating people through trust, fear, urgency or curiosity so they break normal security procedures. It targets human behaviour rather than technical weaknesses.

Watching someone closely, in person or by camera, to observe what they type or read on screen. It can reveal PINs, passwords and confidential information.

Following an authorised person into a restricted building or room without presenting your own credentials. It exploits politeness and is a physical security breach.

An attack that floods a system or network with traffic or requests so that legitimate users cannot access it. A distributed version uses many compromised machines at once.

A network of infected devices, often called bots or zombies, controlled remotely by an attacker. It is commonly used to send spam or launch denial of service attacks.

An attack that takes advantage of a software flaw before the vendor knows about it or has released a fix. Because no patch exists yet, it is hard to defend against.

A weakness in software, hardware, configuration or procedure that an attacker could use to gain access or cause harm. Regular updates and reviews help reduce them.

A secret string of characters used to prove identity when logging in. Strong ones are long, hard to guess and unique to each account.

A password made from a sequence of words, which can be long and memorable while still hard to guess. Length matters more than complicated substitutions.

A tool that stores and fills in login credentials securely, so users can have a different strong password for every account without memorising them all.

Logging in with two or more different kinds of evidence, such as a password plus a code sent to a phone. It blocks access even if the password is stolen.

Using physical characteristics such as a fingerprint, face or iris pattern to verify identity. It is convenient but cannot be changed if the data is ever compromised.

Scrambling data with a mathematical key so that only someone holding the right key can read it. It protects information in transit and at rest.

Converting data into a fixed-length value that acts like a fingerprint. It is used to check whether files have changed and to store passwords without keeping the originals.

A hardware or software barrier that inspects network traffic and allows or blocks connections according to rules. It helps keep unwanted traffic away from a device or network.

A virtual private network creates an encrypted tunnel between a device and a remote server. It protects data on untrusted networks and can hide the user's location.

A software update released to fix bugs or close security holes. Installing patches promptly removes known weaknesses that attackers actively look for.

A separate copy of data kept so it can be restored if files are lost, damaged or encrypted by an attacker. Good practice keeps at least one copy offline.

The rules and settings that decide who may read, change or delete particular resources. It turns the principle of least privilege into practical permissions.

Giving people only the access they genuinely need to do their job, and no more. Limiting rights reduces the damage an accident or compromised account can cause.

A wireless network in a cafe, hotel or airport that anyone nearby can usually join. Traffic may be monitored or intercepted, so sensitive activity should be avoided or protected with a VPN.

The trail of information a person leaves online through posts, searches, purchases and comments. It can persist for years and be seen by future employers or strangers.

A person's right to control what information about them is collected, who can see it and how it is used. Settings, careful sharing and strong passwords all support it.

Using digital channels such as messages, posts or images to harass, threaten or humiliate someone. It can happen at any time and often reaches a wide audience quickly.

The accepted standards of polite and responsible behaviour when communicating online. It includes respecting others, avoiding all-caps shouting and thinking before posting.

The legal right of a creator to control how their work is copied, shared and reused. Downloading or republishing someone else's material without permission can infringe it.