Information Security Definitions

This glossary explains the meaning of key words and phrases that information technology (IT) and business professionals use when discussing IT security and related software products. You can find additional definitions by visiting WhatIs.com or using the search box below.

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  • T

    Trojan horse

    In computing, a Trojan horse is a program downloaded and installed on a computer that appears harmless, but is, in fact, malicious.

  • trusted computing base (TCB)

    A trusted computing base (TCB) is everything in a computing system that provides a secure environment for operations.

  • two-step verification

    Two-step verification is a process that involves two authentication steps performed one after the other to verify that someone or something requesting access is who or what they say they are.

  • Twofish

    Twofish is a symmetric-key block cipher with a block size of 128 bits and variable-length key of size 128, 192 or 256 bits.

  • What is threat detection and response (TDR)? Complete guide

    Threat detection and response (TDR) is the process of recognizing potential cyberthreats and reacting to them before harm can be done to an organization.

  • What is two-factor authentication (2FA)?

    Two-factor authentication (2FA), sometimes referred to as two-step verification or dual-factor authentication, is a security process in which users provide two different authentication factors to verify themselves.

  • U

    user account provisioning

    User account provisioning is a business process for creating and managing access to resources in an information technology (IT) system. To be effective, an account provisioning process should ensure that the creation of accounts and provisioning of access to software and data is is consistent and simple to administer.

  • user authentication

    User authentication verifies the identity of a user attempting to gain access to a network or computing resource by authorizing a human-to-machine transfer of credentials during interactions on a network to confirm a user's authenticity.

  • What is unified threat management (UTM)?

    Unified threat management (UTM) is an information security system that provides a single point of protection against cyberthreats, including viruses, worms, spyware and other malware, as well as network attacks.

  • What is user behavior analytics (UBA)?

    User behavior analytics (UBA) is the tracking, collecting and assessing of user data and activities using monitoring systems.

  • V

    virtual firewall

    A virtual firewall is a firewall device or service that provides network traffic filtering and monitoring for virtual machines (VMs) in a virtualized environment.

  • virtual local area network hopping (VLAN hopping)

    Virtual local area network hopping (VLAN hopping) is a method of attacking the network resources of a VLAN by sending packets to a port not usually accessible from an end system.

  • virus (computer virus)

    A computer virus is a type of malware that attaches itself to a program or file. A virus can replicate and spread across an infected system and it often propagates to other systems, much like a biological virus spreads from host to host.

  • virus hoax

    A virus hoax is a false warning about a computer virus.

  • voice squatting

    Voice squatting is an attack vector for voice user interfaces, or VUIs, that exploits homonyms -- words that sound the same, but are spelled differently -- and input errors -- words that are mispronounced.

  • vulnerability assessment

    A vulnerability assessment is the process of defining, identifying, classifying and prioritizing vulnerabilities in computer systems, applications and network infrastructures.

  • vulnerability disclosure

    Vulnerability disclosure is the practice of reporting security flaws in computer software or hardware.

  • vulnerability management

    Vulnerability management is the process of identifying, assessing, remediating and mitigating security vulnerabilities in software and computer systems.

  • W

    walled garden

    On the internet, a walled garden is an environment that controls the user's access to network-based content and services.

  • WannaCry ransomware

    WannaCry ransomware is a cyber attack that spreads by exploiting vulnerabilities in the Windows operating system.

  • watering hole attack

    A watering hole attack is a security exploit in which the attacker seeks to compromise a specific group of end users by infecting websites that members of the group are known to visit.

  • Web application firewall (WAF)

    A web application firewall (WAF) is a firewall that monitors, filters and blocks Hypertext Transfer Protocol (HTTP) traffic as it travels to and from a website or web application.

  • WebAuthn API

    The Web Authentication API (WebAuthn API) is a credential management application program interface (API) that lets web applications authenticate users without storing their passwords on servers.

  • What is a whaling attack (whaling phishing)?

    A whaling attack, also known as 'whaling phishing' or a 'whaling phishing attack,' is a specific type of phishing attack that targets high-profile employees, such as the chief executive officer (CEO) or chief financial officer, to steal sensitive information from a company.

  • What is WPA3 (Wi-Fi Protected Access 3)?

    WPA3, also known as Wi-Fi Protected Access 3, is the third iteration of a security certification standard developed by the Wi-Fi Alliance. WPA3 is the latest updated implementation of WPA2, which has been in use since 2004.

  • white hat hacker

    A white hat hacker -- or ethical hacker -- is an individual who uses hacking skills to identify security vulnerabilities in hardware, software or networks.

  • Wi-Fi Pineapple

    A Wi-Fi Pineapple is a wireless auditing platform from Hak5 that allows network security administrators to conduct penetration tests.

  • wildcard certificate

    A wildcard certificate is a digital certificate that is applied to a domain and all its subdomains.

  • Windows Defender Exploit Guard

    Microsoft Windows Defender Exploit Guard is antimalware software that provides intrusion protection for Windows 10 OS users.

  • Wired Equivalent Privacy (WEP)

    Wired Equivalent Privacy (WEP) is a security protocol, specified in the IEEE Wireless Fidelity (Wi-Fi) standard, 802.11b.

  • WLAN Authentication and Privacy Infrastructure (WAPI)

    WLAN Authentication and Privacy Infrastructure (WAPI) is a wireless local area network security standard officially supported by the Chinese government.

  • X

    X.509 certificate

    An X.509 certificate is a digital certificate that uses the widely accepted international X.509 public key infrastructure (PKI) standard to verify that a public key belongs to the user, computer or service identity contained within the certificate.

  • Y

    YubiKey

    YubiKey is a security token that enables users to add a second authentication factor to online services from tier 1 vendor partners, including Google, Amazon, Microsoft and Salesforce.

  • Z

    What is the zero-trust security model?

    The zero-trust security model is a cybersecurity approach that denies access to an enterprise's digital resources by default and grants authenticated users and devices tailored, siloed access to only the applications, data, services and systems they need to do their jobs.

  • zero-day vulnerability

    A zero-day vulnerability is a security loophole in software, hardware or firmware that threat actors exploit before the vendors can identify and patch it.

  • Zoombombing

    Zoombombing is a type of cyber-harassment in which an unwanted and uninvited user or group of such users interrupts online meetings on the Zoom video conference app.

  • What is network detection and response (NDR)?

    Network detection and response (NDR) technology continuously scrutinizes network traffic to identify suspicious activity and potentially disrupt an attack.