ICDL Cyber Security (ICDL) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

CIA triad

The three core information security goals: Confidentiality (only authorised access), Integrity (data accurate and unaltered), and Availability (data accessible when needed).

Authentication

The process of verifying that a user or system is who it claims to be, typically through passwords, tokens, or biometrics before access is granted.

Authorisation

The process of deciding which resources and actions a successfully authenticated identity is permitted to use, based on assigned rights or roles.

Multi-factor authentication

Use of two or more authentication factors from different categories, such as a password plus a one-time code, making credential theft alone insufficient for access.

Least privilege

A principle granting each user or process only the minimum access rights required to perform its task, limiting the damage a compromise can cause.

Non-repudiation

The assurance that a party cannot credibly deny having performed an action or sent a message, usually achieved with digital signatures and audit logs.

Vulnerability

A weakness in software, configuration, or process that a threat could exploit to cause harm, such as an unpatched flaw or a weak password policy.

Defence in depth

A layered security approach using independent controls at network, host, application, and data levels so that one failed control does not expose the whole system.

Zero-day vulnerability

A software flaw unknown to the vendor at the time it is exploited, meaning no patch or signature is available to defend against it.

Phishing

A deceptive message, often email, that impersonates a trusted party to trick the recipient into revealing credentials, clicking malicious links, or transferring money.

Spear phishing

A phishing attack customised for a specific individual using researched personal or organisational details, making it far more convincing than bulk phishing.

Whaling

A targeted phishing attack aimed at senior executives or high-value individuals, often seeking large financial transfers or privileged account access.

Social engineering

Manipulating people through trust, authority, or urgency to reveal information or perform actions, exploiting human behaviour rather than technical weaknesses.

Computer worm

Self-replicating malware that spreads across networks without needing a host file, often exploiting unpatched services to infect many systems rapidly.

Trojan horse

Malware disguised as legitimate software that users install willingly; it does not self-replicate but delivers hidden malicious functions such as backdoors.

Ransomware

Malware that encrypts a victim's data or locks systems and demands payment for restoration, with offline backups being the reliable defence.

Man-in-the-middle attack

An attack where a third party secretly intercepts and possibly alters communications between two parties, often on unsecured networks or via spoofed access points.

Denial-of-service attack

An attack that floods a service with traffic or requests to exhaust its resources, making it unavailable to legitimate users; a DDoS uses many compromised hosts.

Keylogger

Hardware or software that secretly records keystrokes to capture passwords and other sensitive input, often installed via malware or a physical device.

Risk treatment options

The four standard responses to risk: avoid the activity, reduce it with controls, transfer it (for example insurance), or accept the residual risk.

Encryption at rest

Protecting stored data, such as files or a full disk, by converting it to ciphertext so it is unreadable without the correct decryption key.

Encryption in transit

Protecting data while it travels across a network using protocols such as TLS, so intercepted traffic cannot be read or altered by eavesdroppers.

Password manager

A tool that stores credentials in an encrypted vault unlocked by one master password, enabling long, unique passwords for every site without memorising them.

3-2-1 backup rule

A backup strategy keeping at least three copies of data, on two different media types, with one copy stored off-site or offline.

Full-disk encryption

Encrypting an entire storage drive so that its contents are unreadable without the correct key or passphrase, protecting data if a device is lost or stolen.

Patching

Applying vendor updates that fix known vulnerabilities, reducing the window during which attackers can exploit disclosed flaws in software or systems.

Firewall

A security control that permits or blocks network traffic according to defined rules; host firewalls protect one device, network firewalls protect a segment.

Antimalware signatures

Patterns used by antivirus software to recognise known malicious code; they must be updated regularly because new malware appears continuously.

HTTPS padlock meaning

The padlock indicates the connection is encrypted with TLS; it does not prove the website operator is trustworthy or legitimate.

Typosquatting

Registering domain names that closely resemble legitimate ones, such as misspellings, to deceive users into visiting fraudulent sites and entering credentials.

Digital footprint

The trail of data left by a person's online activity, which persists over time and can be copied, so full deletion is never guaranteed.

Public Wi-Fi risk

Untrusted wireless networks can be monitored or spoofed by attackers, so sensitive activity should use a VPN or mobile hotspot and auto-join should be disabled.