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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  • P

    public key

    In cryptography, a public key is a large numerical value that is used to encrypt data.

  • Public-Key Cryptography Standards (PKCS)

    Public-Key Cryptography Standards (PKCS) are a set of standard protocols, numbered from 1 to 15.

  • pure risk

    Pure risk refers to risks that are beyond human control and result in a loss or no loss with no possibility of financial gain.

  • What is a potentially unwanted program (PUP)?

    A potentially unwanted program (PUP) is a program that may be unwanted, despite the possibility that users consented to download it.

  • What is a public key certificate?

    A public key certificate is a digitally signed document that serves to validate the sender's authorization and name.

  • What is passwordless authentication?

    Passwordless authentication allows a user to sign into a service without using a password. This is often done using certificates, security tokens, one-time passwords (OTPs) or biometrics.

  • What is PCI DSS (Payment Card Industry Data Security Standard)?

    The Payment Card Industry Data Security Standard (PCI DSS) is a widely accepted set of policies and procedures intended to optimize the security of credit, debit and cash card transactions and protect cardholders against misuse of their personal information.

  • What is PKI (public key infrastructure)?

    PKI (public key infrastructure) is the underlying framework that enables the secure exchange of information over the internet using digital certificates and public key encryption.

  • Q

    quantum cryptography

    Quantum cryptography is a method of encryption that uses the naturally occurring properties of quantum mechanics to secure and transmit data.

  • quantum key distribution (QKD)

    Quantum key distribution (QKD) is a secure communication method for exchanging encryption keys only known between shared parties.

  • quantum supremacy

    Quantum supremacy is the experimental demonstration of a quantum computer's dominance and advantage over classical computers by performing calculations previously impossible at unmatched speeds.

  • R

    RADIUS (Remote Authentication Dial-In User Service)

    RADIUS (Remote Authentication Dial-In User Service) is a client-server protocol and software that enables remote access servers to communicate with a central server to authenticate dial-in users and authorize their access to the requested system or service.

  • RAT (remote access Trojan)

    A RAT (remote access Trojan) is malware an attacker uses to gain full administrative privileges and remote control of a target computer.

  • registration authority (RA)

    A registration authority (RA) is an authority in a network that verifies user requests for a digital certificate and tells the certificate authority (CA) to issue it.

  • remote access

    Remote access is the ability for an authorized person to access a computer or network from a geographical distance through a network connection.

  • Report on Compliance (ROC)

    A Report on Compliance (ROC) is a form that must be completed by all Level 1 Visa merchants undergoing a PCI DSS (Payment Card Industry Data Security Standard) audit.

  • residual risk

    Residual risk is the risk that remains after efforts to identify and eliminate some or all types of risk have been made.

  • reverse brute-force attack

    A reverse brute-force attack is a type of brute-force attack in which an attacker uses a common password against multiple usernames in an attempt to gain access to a network.

  • Rijndael

    Rijndael (pronounced rain-dahl) is an Advanced Encryption Standard (AES) algorithm.

  • risk analysis

    Risk analysis is the process of identifying and analyzing potential issues that could negatively impact key business initiatives or projects.

  • risk appetite

    Risk appetite is the amount of risk an organization or investor is willing to take in pursuit of objectives it deems have value.

  • risk assessment

    Risk assessment is the process of identifying hazards that could negatively affect an organization's ability to conduct business.

  • risk avoidance

    Risk avoidance is the elimination of hazards, activities and exposures that can negatively affect an organization and its assets.

  • risk exposure

    Risk exposure is the quantified potential loss from business activities currently underway or planned.

  • risk map (risk heat map)

    A risk map (risk heat map) is a data visualization tool for communicating specific risks an organization faces.

  • risk profile

    A risk profile is a quantitative analysis of the types of threats an organization, asset, project or individual faces.

  • risk reporting

    Risk reporting is a method of identifying risks tied to or potentially impacting an organization's business processes.

  • risk-based authentication (RBA)

    Risk-based authentication (RBA) is an authentication method in which varying levels of stringency are applied to a system’s authentication process based on the likelihood that access to that system could result in its compromise.

  • risk-based patch management (RBPM)

    Risk-based patch management (RBPM) is an approach to implementing patches to fix software code that prioritizes patches that address security issues posing the highest risk to the organization.

  • risk-based vulnerability management (RBVM)

    Risk-based vulnerability management (RBVM) is an approach to identifying and addressing security vulnerabilities in an organization's IT environment that prioritizes remediating vulnerabilities that pose the greatest risk.

  • role mining

    Role mining is the process of analyzing user-to-resource mapping data to determine or modify user permissions for role-based access control (RBAC) in an enterprise... (Continued)

  • rootkit

    A rootkit is a program or a collection of malicious software tools that give a threat actor remote access to and control over a computer or other system.

  • RSA algorithm (Rivest-Shamir-Adleman)

    The RSA algorithm (Rivest-Shamir-Adleman) is the basis of a cryptosystem -- a suite of cryptographic algorithms that are used for specific security services or purposes -- which enables public key encryption and is widely used to secure sensitive data, particularly when it is being sent over an insecure network, such as the internet.

  • What is ransomware? How it works and how to remove it

    Ransomware is a type of malware that locks and encrypts a victim's data, files, devices or systems, rendering them inaccessible and unusable until the attacker receives a ransom payment.

  • What is risk management? Importance, benefits and guide

    Risk management is the process of identifying, assessing and controlling threats to an organization's capital, earnings and operations.

  • What is role-based access control (RBAC)?

    Role-based access control (RBAC) is a method of restricting network access based on the roles of individual users within an enterprise.

  • S

    sandbox

    A sandbox is an isolated testing environment that enables users to run programs or open files without affecting the application, system or platform on which they run.

  • screened subnet

    A screened subnet, or triple-homed firewall, refers to a network architecture where a single firewall is used with three network interfaces.

  • script kiddie

    Script kiddie is a derogative term that computer hackers coined to refer to immature, but often just as dangerous, exploiters of internet security weaknesses.

  • Secure Electronic Transaction (SET)

    Secure Electronic Transaction (SET) is a system and electronic protocol to ensure the integrity and security of transactions conducted over the internet.

  • Secure Sockets Layer certificate (SSL certificate)

    A Secure Sockets Layer certificate (SSL certificate) is a small data file installed on a web server that allows for a secure, encrypted connection between the server and a web browser.

  • Securities and Exchange Commission (SEC)

    The Securities and Exchange Commission (SEC) is the U.S. government agency that oversees the nation's securities industry.

  • security

    Security for information technology (IT) refers to the methods, tools and personnel used to defend an organization's digital assets.

  • security analytics

    Security analytics is a cybersecurity approach that uses data collection, data aggregation and analysis tools for threat detection and security monitoring.

  • Security Assertion Markup Language (SAML)

    Security Assertion Markup Language (SAML) is an open standard for sharing security information about identity, authentication and authorization across different systems.

  • security awareness training

    Security awareness training is a strategic approach IT and security professionals take to educate employees and stakeholders on the importance of cybersecurity and data privacy.

  • security clearance

    A security clearance is an authorization that allows access to information that would otherwise be forbidden.

  • security identifier (SID)

    In the context of Windows computing and Microsoft Active Directory (AD), a security identifier (SID) is a unique value that is used to identify any security entity that the operating system (OS) can authenticate.

  • security information management (SIM)

    Security information management (SIM) is the practice of collecting, monitoring and analyzing security-related data from computer logs and various other data sources.

  • security operations center (SOC)

    A security operations center (SOC) is a command center facility in which a team of information technology (IT) professionals with expertise in information security (infosec) monitors, analyzes and protects an organization from cyberattacks.

  • security policy

    A security policy is a document that states in writing how a company plans to protect its physical and information technology (IT) assets.

  • security posture

    Security posture refers to an organization's overall cybersecurity strength and how well it can predict, prevent and respond to ever-changing cyberthreats.

  • security token

    A security token is a physical or wireless device that provides two-factor authentication (2FA) for users to prove their identity in a login process.

  • self-sovereign identity

    Self-sovereign identity (SSI) is a model for managing digital identities in which individuals or businesses have sole ownership over the ability to control their accounts and personal data.

  • Sender Policy Framework (SPF)

    Sender Policy Framework (SPF) is a protocol designed to restrict who can use an organization's domain as the source of an email message.

  • shadow password file

    A shadow password file, also known as /etc/shadow, is a system file in Linux that stores encrypted user passwords and is accessible only to the root user, preventing unauthorized users or malicious actors from breaking into the system.

  • Shared Key Authentication (SKA)

    Shared Key Authentication (SKA) is a process by which a computer can gain access to a wireless network that uses the Wired Equivalent Privacy (WEP) protocol.

  • shoulder surfing

    Shoulder surfing is using direct observation techniques, such as looking over someone's shoulder, to get information.

  • side-channel attack

    A side-channel attack is a security exploit that aims to gather information from or influence the program execution of a system by measuring or exploiting indirect effects of the system or its hardware -- rather than targeting the program or its code directly.

  • single sign-on (SSO)

    Single sign-on (SSO) is a session and user authentication service that permits a user to use one set of login credentials -- for example, a username and password -- to access multiple applications.

  • single-factor authentication (SFA)

    Single-factor authentication (SFA) is a process for securing access to a given system, such as a network or website, that identifies the party requesting access through only one category of credentials.

  • smart card

    A smart card is a physical card that has an embedded integrated chip that acts as a security token.

  • snooping

    Snooping, in a security context, is unauthorized access to another person's or company's data.

  • SOAR (security orchestration, automation and response)

    SOAR (security orchestration, automation and response) is a stack of compatible software programs that enables an organization to collect data about security threats and respond to security events with little or no human assistance.

  • SOC 1 (System and Organization Controls 1)

    System and Organization Controls 1, or SOC 1 (pronounced "sock one"), aims to control objectives within a SOC 1 process area and documents internal controls relevant to an audit of a user entity's financial statements.

  • SOC 2 (System and Organization Controls 2)

    SOC 2 (System and Organization Controls 2), pronounced "sock two," is a voluntary compliance standard for ensuring that service providers properly manage and protect the sensitive data in their care.

  • SOC 3 (System and Organization Controls 3)

    A System and Organization Controls 3 (SOC 3) report outlines information related to a service organization's internal controls for security, availability, processing integrity, confidentiality and privacy.

  • social engineering

    Social engineering is an attack vector that relies heavily on human interaction and often involves manipulating people into breaking normal security procedures and best practices to gain unauthorized access to systems, networks or physical locations or for financial gain.

  • social media policy

    A social media policy is a corporate code of conduct that provides guidelines for employees who post content on the internet either as part of their job or as a private person.

  • soft token

    A soft token is a software-based security token that generates a single-use login personal identification number (PIN).

  • spam filter

    A spam filter is a program used to detect unsolicited, unwanted and virus-infected emails and prevent those messages from getting to a user's inbox.

  • spear phishing

    Spear phishing is a malicious email spoofing attack that targets a specific organization or individual, seeking unauthorized access to sensitive information.

  • speculative risk

    Speculative risk is a type of risk the risk-taker takes on voluntarily and will result in some degree of profit or loss.

  • spyware

    Spyware is a type of malicious software -- or malware -- that is installed on a computing device without the end user's knowledge.

  • SSAE 16

    The Statement on Standards for Attestation Engagements No. 16 (SSAE 16) is a set of auditing standards and guidance on using the standards, published by the Auditing Standards Board (ASB) of the American Institute of Certified Public Accountants (AICPA), for redefining and updating how service companies report on compliance controls.

  • stealth virus

    A stealth virus is a computer virus that uses various mechanisms to avoid detection by antivirus software.

  • steganography

    Steganography is the technique of hiding data within an ordinary, nonsecret file or message to avoid detection; the hidden data is then extracted at its destination.

  • Structured Threat Information eXpression (STIX)

    Structured Threat Information eXpression (STIX) is a standardized Extensible Markup Language (XML) programming language for conveying data about cybersecurity threats in a way that can be easily understood by both humans and security technologies.

  • sudo (su 'do')

    Sudo is a command-line utility for Unix and Unix-based operating systems such as Linux and macOS.

  • supercookie

    A supercookie is a type of tracking cookie inserted into an HTTP header to collect data about a user's internet browsing history and habits.

  • supply chain attack

    A supply chain attack is a type of cyber attack that targets organizations by focusing on weaker links in an organization's supply chain.

  • SYN flood attack

    A SYN flood attack is a type of denial-of-service (DoS) attack on a computer server.

  • What is a session key?

    A session key is an encryption and decryption key that is randomly generated to ensure the security of a communications session between a user and another computer or between two computers.

  • What is a spam trap?

    A spam trap is an email address that's used to identify and monitor spam email. It's also a type of honeypot because it uses a fake email address to bait spammers.

  • What is a SSL (secure sockets layer)?

    Secure sockets layer (SSL) is a networking protocol designed for securing connections between web clients and web servers over an insecure network, such as the internet.

  • What is a stream cipher?

    A stream cipher is an encryption method in which data is encrypted one byte at a time.

  • What is an SSL VPN (Secure Sockets Layer virtual private network)?

    An SSL VPN is a type of virtual private network (VPN) that uses the Secure Sockets Layer (SSL) protocol -- or, more often, its successor, the Transport Layer Security (TLS) protocol -- in standard web browsers to provide secure, remote access VPN capability.

  • What is SecOps? Everything you need to know

    SecOps, formed from a combination of security and IT operations staff, is a highly skilled team focused on monitoring and assessing risk and protecting corporate assets, often operating from a security operations center, or SOC.

  • What is security information and event management (SIEM)?

    Security information and event management (SIEM) is an approach to security management that combines security information management (SIM) and security event management (SEM) functions into one security management system.

  • What is SSH (Secure Shell) and How Does It Work?

    SSH (Secure Shell or Secure Socket Shell) is a network protocol that gives users -- particularly systems administrators -- a secure way to access a computer over an unsecured network.

  • T

    threat modeling

    Threat modeling is a procedure for optimizing application, system or business process security by identifying objectives and vulnerabilities, and then defining countermeasures to prevent or mitigate the effects of threats to the system.

  • three-factor authentication (3FA)

    Three-factor authentication (3FA) is the use of identity-confirming credentials from three separate categories of authentication factors -- typically, the knowledge, possession and inherence categories.

  • time-based one-time password

    A time-based one-time password (TOTP) is a temporary passcode generated by an algorithm that uses the current time of day as one of its authentication factors.

  • timing attack

    A timing attack is a type of side-channel attack that exploits the amount of time a computer process runs to gain knowledge about or access a system.

  • tokenization

    Tokenization is the process of replacing sensitive data with unique identification symbols that retain all the essential information about the data without compromising its security.

  • total risk

    Total risk is an assessment that identifies all the risk factors associated with pursuing a specific course of action.

  • Transport Layer Security (TLS)

    Transport Layer Security (TLS) is an Internet Engineering Task Force (IETF) standard protocol that provides authentication, privacy and data integrity between two communicating computer applications.

  • TrickBot malware

    TrickBot is sophisticated modular malware that started as a banking Trojan but has evolved to support many different types of attacks, including ransomware.

  • triple extortion ransomware

    Triple extortion ransomware is a type of ransomware attack where a cybercriminal extorts their victim multiple times, namely by encrypting data, exfiltrating data to expose and threatening a third attack vector.

  • Trojan horse

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