Authentication Glossary

Browse 96 authentication terms defined in plain English, from the cultural dictionary of computing.

96 Authentication Terms

2FA Fatigue
The frustration or desensitization users experience from repeated two-factor authentication prompts, which can lead them to approve push notifications without...
802.1X
802.1X is an IEEE standard for port-based network access control that provides an authentication framework for devices connecting to a local area network (LAN)...
Access Token
A credential used by a client or service to access protected resources on behalf of a user or itself, often with scoped permissions and limited lifetime. In...
Account Enumeration
A technique for discovering whether specific user accounts exist by observing differences in responses, timing, or error messages during login, signup, or...
Account Lockout
A security control that temporarily or permanently blocks account access after too many failed authentication attempts. Lockout policies can slow brute-force...
Anti-Replay
Intended to prevent replay attacks, where a valid captured message or credential is resent later to fraudulently repeat an action. Anti-replay protections...
API Key vs Token
Two approaches to API authentication. API keys are long-lived, opaque strings tied to an account or project -- simple but risky if leaked (no expiration)....
API Token
A secret or signed token used to authenticate and authorize requests made to an API. API tokens vary in format and scope, but they commonly represent service...
Auth Dance
A joking description of the awkward sequence of redirects, tokens, prompts, and confirmations involved in authentication or authorization flows. In developer...
Authentication Factor
A category of evidence used to verify identity, such as something you know, have, or are. Multiple authentication factors are combined in MFA to make account...
Authentication Flow
The sequence of steps by which a user or system proves identity and receives a session, token, or other authenticated state. Authentication flows often include...
Authentication Handler
A component that receives authentication-related requests and coordinates validation, token issuance, redirects, or session setup. Authentication handlers...
Authentication Library
A reusable library that implements common authentication capabilities such as token validation, session management, OAuth flows, or password hashing....
Authentication Middleware
Middleware that intercepts requests to verify identity, parse credentials, establish user context, or reject unauthenticated calls before application logic...
Authentication Protocol
A formal method or protocol used to verify identity and establish trust between parties, such as Kerberos, OAuth flows, or certificate-based schemes. The...
Authentication Provider
A service or component responsible for verifying identity and often issuing tokens, assertions, or session information to applications. Authentication...
Authentication Service
A dedicated service that handles login, credential validation, token issuance, session management, or identity federation for one or more applications....
Behavioral Biometrics
Behavioral Biometrics is authentication signals derived from how a person types, moves, swipes, or otherwise interacts with a system. Security teams use it to...
Biometric Authentication
Biometric Authentication is identity verification based on physical or behavioral traits such as fingerprints, face patterns, or typing rhythm. Security teams...
Biometric Bypass
A technique for defeating or circumventing biometric authentication, such as fingerprint, face, or voice verification, without legitimately matching the...
Brute Force Protection
Controls designed to stop repeated guess attempts against passwords, codes, or other secrets, such as rate limits, lockouts, CAPTCHAs, or IP reputation checks....
CAPTCHA
CAPTCHA is a challenge mechanism meant to distinguish human activity from automated abuse during login, signup, or scraping workflows. Security teams use it to...
Challenge-Response
Challenge-Response is an authentication pattern in which a verifier sends a nonce or challenge and validates a computed response. Security teams use it to...
Challenge Token
A short-lived token used to prove that a client is responding to a legitimate challenge or participating in a valid interaction. Challenge tokens appear in...
Cookie Hijacking
The theft or misuse of a session cookie so an attacker can impersonate a logged-in user. It can result from XSS, insecure transport, session fixation, or other...
Credential
A secret or proof of identity used to authenticate a user, service, or application, such as a password, token, certificate, or API key. Credentials must be...
Credential Cache
A stored set of authentication material kept to support reuse, offline access, or faster authentication workflows. Credential caches improve usability, but if...
Credential Provider
A component or service that supplies credentials to an application, often by loading them from environment variables, metadata services, secret stores, or...
Cryptographic Signature
A value produced with a private key that lets others verify integrity and origin using the corresponding public key. Cryptographic signatures are fundamental...
Default Password
A vendor-supplied password that ships with a device, application, or service before the owner changes it. Default passwords are a common initial-access path...
Digital Identity
The representation of a person, device, service, or organization in digital systems through accounts, credentials, attributes, and trust relationships....
Digital Signature
A cryptographic scheme that proves a message was created by a known sender (authentication) and wasn't altered in transit (integrity). The signer hashes the...
DKIM
DKIM is a mail authentication standard that lets receiving systems verify a signed domain-level message header. Security teams use it to enforce trust, reduce...
DMARC
DMARC is an email authentication policy standard that builds on SPF and DKIM to tell receivers how to handle failing mail. Security teams use it to enforce...
EAP
EAP is an authentication framework used on network access links such as Wi-Fi, VPN, and 802.1X environments. Security teams use it to enforce trust, reduce...
Email Authentication
Email Authentication is the set of mechanisms used to verify whether email claiming a domain is legitimately authorized by that domain. Security teams use it...
Email Security
The set of controls used to protect email systems and users from spoofing, phishing, malware, account takeover, and data loss. It includes user training,...
Enrollment
The process of registering a user, device, token, biometric factor, or certificate into an identity or security system so it can be recognized and trusted...
Face ID Security
The security properties and defenses of facial-recognition authentication systems such as Apple's Face ID, including liveness checks, infrared sensing, spoof...
Federated Identity
Federated Identity is an identity model where one domain accepts authentication assertions issued by another trusted domain. Security teams use it to enforce...
Fingerprint Scanner
A biometric sensor that captures and matches fingerprint characteristics for authentication or identity verification. Security discussions around fingerprint...
Hardware Key
A physical security device used to authenticate a user or perform cryptographic operations, often through standards such as FIDO2 or smart-card protocols....
Hardware Token
A physical token that generates one-time codes or performs secure cryptographic authentication for user access. Hardware tokens are widely used where stronger...
HMAC
Hash-based Message Authentication Code — a construction that combines a cryptographic hash function with a secret key to produce a message authentication code....
HMAC Authentication
HMAC Authentication is message authentication based on a keyed hash so a receiver can verify integrity and shared-secret knowledge. Security teams use it to...
Identity and Access Management
Identity and Access Management is the set of processes and systems used to govern identities, roles, authentication, and authorization. Security teams use it...
Identity Management
The administration of identities, credentials, authentication flows, and access relationships across systems and services. Identity management includes...
Identity Provider
Identity Provider is a service that authenticates users and issues identity assertions or tokens to relying applications. Security teams use it to enforce...
Identity Verification
The act of checking that a person or entity matches a claimed identity at a particular moment, often during onboarding, recovery, or high-risk transactions. It...
Impersonation
The act of pretending to be another user, service, or trusted entity in order to gain access, trust, or influence. Impersonation can occur through stolen...
JWT
JWT, or JSON Web Token, is a compact, URL-safe token format for securely transmitting claims between parties. A JWT consists of three Base64-encoded parts...
Kerberos
Kerberos is a ticket-based network authentication protocol that relies on a trusted key distribution center. Security teams use it to enforce trust, reduce...
Keycloak
An open-source identity and access-management platform used for authentication, SSO, and user federation.
LDAP
Short for Lightweight Directory Access Protocol, the protocol used to query and manage directory information such as users, groups, devices, and permissions....
Lockout Policy
A policy that temporarily or permanently blocks an account after too many failed login attempts, intended to slow password guessing and credential stuffing....
Login Attempt
A recorded event in which a user, device, or service tries to authenticate to a system, regardless of success or failure. Security teams monitor login attempts...
Logon Event
A system-recorded event indicating that a user or service has logged on, often used specifically in Windows auditing contexts. Logon events help investigators...
Long-Lived Token
An access, refresh, or API token with a relatively long validity period before expiration or forced rotation. Long-lived tokens improve convenience and service...
Masquerade Attack
An attack in which an adversary pretends to be a legitimate user, service, process, or trusted artifact to gain access or avoid suspicion. Masquerading can...
Message Authentication Code
Message Authentication Code is a keyed cryptographic check that proves message integrity and shared-secret possession. Security teams use it to enforce trust,...
mTLS
Mutual TLS — an extension of standard TLS where both the client and server present certificates to authenticate each other (standard TLS only authenticates the...
Multi-Factor
Describing authentication that requires more than one category of evidence, such as something you know, have, or are, rather than relying on a single password...
Multi-Factor Authentication
Authentication requiring two or more independent verification factors: something you know (password), something you have (phone/key), something you are...
Mutual Authentication
Mutual Authentication is authentication in which each communicating party verifies the identity of the other. Security teams use it to enforce trust, reduce...
Mutual TLS
Mutual TLS is a TLS mode in which both client and server present certificates and authenticate each other. Security teams use it to enforce trust, reduce...
Navigation Guard
A hook in a client-side router — most prominently Vue Router's `beforeEach`, `beforeEnter`, and `beforeRouteLeave` — that intercepts navigation events and can...
Non-Repudiation
A property that provides strong evidence that a specific party performed an action or sent a message, making it difficult for them to deny involvement later....
NTLM
NTLM is a legacy Microsoft authentication protocol that uses challenge-response and is frequently targeted for relay or cracking. Security teams use it to...
OAuth
OAuth is an open standard for access delegation that allows users to grant third-party applications limited access to their accounts on another service without...
OIDC
OpenID Connect — an identity layer built on top of OAuth 2.0 that adds a standardized ID token (a signed JWT containing user claims like email and name) to the...
One-Time Password
A password or numeric code intended for a single login or short validity window, often generated by hardware tokens, authenticator apps, or delivered out of...
OTP
One-Time Password — a dynamically generated code valid for a single login session or transaction. TOTP (time-based) and HOTP (counter-based) are the two main...
OTP Bypass
OTP Bypass is a technique for defeating one-time password checks through logic flaws, phishing, interception, or recovery abuse. Security teams use it to...
Out-of-Band Authentication
An authentication method that confirms identity over a separate channel from the main login session. It shows up in application security, identity,...
Out-of-Band Channel
A separate communication path used for verification, recovery, or coordination outside the primary channel being protected or monitored. Out-of-band channels...
Passkey
A passwordless authentication credential based on WebAuthn/FIDO2 that uses public key cryptography. The private key never leaves the user's device (or syncs...
Password Complexity
The rules or characteristics that define how varied a password's characters must be, such as length, symbol use, and mixture of character types. Complexity...
Password Hashing
The practice of transforming a plaintext password into an irreversible, fixed-length digest using a deliberately slow, salted algorithm — such as bcrypt,...
Password Lockout
A condition in which an account is temporarily or permanently blocked after too many failed authentication attempts. Password lockout helps slow guessing...
Password Recovery
The process by which a user regains access to an account when the password is forgotten or unavailable. Password recovery is a high-risk path because weak...
Password Reset
The act of replacing an existing password with a new one, either by the user or through an administrative or automated recovery workflow. Password reset flows...
Physical Token
A tangible object used in authentication or access control, such as a hardware OTP device, smart card, badge, or FIDO key. Physical tokens can improve security...
PIN
A short numeric secret used to verify a user's identity during access to a device, account, or transaction. It shows up in application security, identity,...
PIN Entry
The process or interface through which a user enters a personal identification number to authenticate a transaction, device, or account. PIN entry security...
Proxy Authentication
The process by which a proxy server verifies the identity of the user, device, or service before forwarding traffic on its behalf. Proxy authentication is used...
RADIUS
Short for Remote Authentication Dial-In User Service, a protocol commonly used for centralized authentication, authorization, and accounting in network access...
Realm
An embedded, object-oriented mobile database (now part of MongoDB's Atlas Device SDK) that stores data as native objects rather than rows, supports real-time...
Relay Attack
An attack in which communications between a legitimate party and a trusted system are forwarded through an attacker-controlled channel so proximity or...
Remote Access
The ability to connect to and use systems, networks, or data from another location rather than from the local environment. Remote access is essential for...
Route Guard
A hook in a client-side router (notably Angular's CanActivate, CanDeactivate interfaces) that runs before a navigation completes, allowing the application to...
SSO
Single Sign-On -- an authentication scheme where one login grants access to multiple related applications without re-authenticating. Implemented via SAML,...
Time-Based One-Time Password
A short authentication code generated from a shared secret and the current time window. It shows up in application security, identity, infrastructure, or...
TOTP
Time-based One-Time Password — an algorithm that generates a short-lived password from a shared secret and the current time. The math behind those 6-digit...
Two-Factor Authentication
An authentication scheme requiring two distinct forms of verification — typically something you know (password) and something you have (phone, hardware key) —...
Wallet
A software or hardware tool that stores cryptographic private keys and manages digital assets (cryptocurrency, NFTs, digital identity). Does not actually...
Wi-Fi Protected Access
A family of wireless security protocols used to authenticate devices and encrypt Wi-Fi traffic. It shows up in application security, identity, infrastructure,...

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