User Authentication: Methods, Types & Best Practices
User authentication is one of the foundations of digital security because almost every online service needs a reliable way to determine who is trying to access an account or system. Whether someone signs into an email account, online bank, workplace application, cloud platform, or smartphone, an authentication process checks evidence that supports the user’s claimed identity. Traditional authentication relied heavily on usernames and passwords, but modern systems increasingly use multi-factor authentication, biometrics, security keys, passkeys, one-time passwords, and risk-based authentication. These additional methods can reduce the damage caused by stolen or reused passwords while also making sign-in more convenient when implemented carefully.
Authentication technology continues to evolve as phishing, credential theft, and account takeover techniques become more sophisticated. NIST’s current Digital Identity Guidelines, published as SP 800-63B-4 in July 2025, emphasize stronger authentication assurance and phishing-resistant options for higher-risk environments. Passkeys are also becoming an important passwordless option because they use public-key cryptography and are designed to resist phishing rather than depending on users recognizing fraudulent login pages. This guide explains what user authentication is, how it works, major authentication methods and factors, MFA, biometrics, passkeys, common security threats, and current authentication best practices for businesses and application developers.
What Is User Authentication?
User authentication is the process of verifying that a person, device, or other entity attempting to access a system is genuinely associated with the identity it claims. OWASP defines authentication as validating one or more authenticators, such as passwords, fingerprints, or security tokens, that support an identity claim. A user typically begins by providing an identifier such as a username or email address and then presents one or more pieces of evidence. The system checks that evidence against the credentials or cryptographic information associated with the account. If verification succeeds, the system can create an authenticated session and allow access according to that user’s permissions.
Authentication should not be confused with simply identifying a user. Typing an email address tells the application which account someone claims to own, but it does not prove that the person actually controls that account. The proof normally comes from an authenticator such as a password, passkey, security key, authentication app, or biometric-enabled device. This distinction matters because attackers often know victims’ usernames or email addresses. Security therefore depends on protecting the evidence required to prove account control rather than treating an identifier itself as confidential. A well-designed authentication system assumes that usernames may be discoverable and makes unauthorized verification difficult even when the attacker knows which account to target.
Authentication is also different from identity proofing, which establishes whether a digital identity belongs to a particular real-world person. A social platform may allow users to create pseudonymous accounts without confirming a passport or national identity document, yet still authenticate those accounts every time users log in. By contrast, a regulated financial service may perform identity verification during registration before binding authentication credentials to the verified customer. OWASP distinguishes digital identity, identity proofing, and authentication as related but separate concepts. Organizations should therefore determine how much real-world identity assurance they need independently from deciding how users will authenticate after enrollment.
Once a user successfully authenticates, the application usually creates a session so the person does not need to present credentials with every page request. The session identifier effectively represents the authenticated user for the duration of that session, which makes session protection extremely important. OWASP notes that after authentication, a session token can temporarily become equivalent to the strongest credential the user presented because possession of that token may allow someone to impersonate the user. Secure authentication therefore does not end at the login screen. Session creation, storage, expiration, logout, reauthentication, and protection against token theft are all part of maintaining trustworthy access.
The purpose of authentication is ultimately to create an appropriate level of confidence that the current user controls credentials previously bound to the account. Different applications need different levels of confidence because the impact of unauthorized access varies dramatically. A public discussion forum and an online banking platform do not face the same consequences when authentication fails. NIST addresses this through Authentication Assurance Levels, ranging from AAL1 for basic assurance to AAL3 for environments requiring very high confidence and phishing-resistant cryptographic authentication. Effective authentication security should therefore be based on risk rather than applying exactly the same controls to every account and transaction.
How Does User Authentication Work?
The authentication process usually begins when a user identifies the account they want to access. This may involve entering a username, email address, phone number, employee identifier, or selecting an existing account. The application then determines which authentication methods are available for that account. A traditional login might request a password, while a passwordless service could prompt the device for a passkey. Enterprise applications may redirect the user to a centralized identity provider through single sign-on. Regardless of the interface, the objective is to obtain sufficient proof that the person currently signing in controls an authenticator that was previously registered to the account.
With password authentication, the server should not store the user’s actual password in readable form. Instead, properly designed systems store a protected password representation created through a password-hashing process and compare that result when the user signs in. This reduces the damage if a credential database is exposed because attackers do not immediately receive every user’s plaintext password. Password storage is only one part of the process, however, because login pages must also use encrypted transport so credentials cannot be intercepted while traveling across networks. OWASP specifically recommends using TLS or another strong protected transport throughout login and authenticated application pages.
With possession-based authentication, the system verifies that the user controls something associated with the account. This could be a smartphone containing an authentication app, a hardware security key, a smart card, a cryptographic certificate, or another registered authenticator. One-time-password systems generate codes that change over time or per authentication event, while security keys and passkeys use cryptographic challenge-response protocols. The latter approach can provide stronger resistance to phishing because the secret credential does not need to be typed into a webpage. NIST explains that authentication methods requiring users to manually enter OTP outputs are not considered phishing-resistant because fraudulent sites can potentially relay those codes.
If multiple factors are required, the service verifies evidence from independent authentication categories before allowing access. A user might enter a password and then approve a request using a registered security key, combining something the person knows with something the person has. Two passwords or a password plus a PIN would not normally constitute true MFA because both are knowledge factors. OWASP emphasizes that multi-factor authentication requires more than one type of evidence and that the factors should be independent enough that one attack cannot easily compromise all of them. Successful verification then allows the service to create an authenticated session.
Authentication does not necessarily stop after the initial login. Applications may require step-up authentication or reauthentication before high-risk actions such as changing account recovery information, disabling MFA, accessing sensitive records, or elevating privileges. OWASP recommends reauthentication following suspicious activity and before sensitive operations where stronger assurance is appropriate. Risk-based systems may also consider contextual signals such as device history, IP reputation, location changes, or unusual behavior when deciding whether additional verification is needed. The best authentication flow therefore balances security with usability by introducing additional friction primarily when the level of risk justifies it.
Main Types and Methods of User Authentication
Password authentication remains the most familiar method because it requires relatively little specialized hardware and is supported across almost every digital platform. A password represents something the user knows and is compared with the protected credential associated with the account. Its simplicity also creates major weaknesses because people may reuse passwords, choose predictable phrases, disclose credentials to phishing sites, or have passwords exposed through breaches. OWASP advises organizations to assume that user passwords may eventually be compromised and design authentication systems with additional protections. Passwords can remain useful, but modern security strategies increasingly avoid treating them as the only defense for valuable accounts.
One-time passwords, commonly called OTPs, are temporary codes used to verify account access. Time-based one-time passwords generated by authenticator applications are particularly common, while some services send codes through SMS, email, or another communication channel. Because the code changes frequently, stealing an old OTP generally does not allow indefinite access. However, OTPs can still be captured through real-time phishing attacks in which a fraudulent website asks the user for the code and immediately relays it to the legitimate service. NIST therefore does not classify manually entered OTP authenticators as phishing-resistant. They can provide useful protection beyond passwords while remaining weaker than properly implemented cryptographic authentication.
Biometric authentication uses a measurable physical or behavioral characteristic associated with the user. Familiar examples include fingerprints, facial recognition, iris patterns, and sometimes voice or behavioral characteristics. Biometrics can make authentication convenient because users do not need to memorize another secret, but biometric systems must be designed carefully because physical characteristics cannot simply be changed like a compromised password. NIST also makes an important distinction at higher assurance levels: a biometric characteristic is not treated as an authenticator by itself and should be used with a physical authenticator. Many modern devices therefore use biometrics locally to unlock a cryptographic credential stored on the device.
Hardware security keys and smart cards provide possession-based authentication through dedicated physical devices. Instead of asking users to copy a code from one screen to another, modern FIDO security keys can perform a cryptographic challenge-response process tied to the legitimate service. This makes them much harder to phish than passwords and OTP codes. They are commonly used for administrators, enterprise employees, developers, journalists, financial users, and others who require stronger protection against targeted attacks. Their disadvantages include purchase costs, replacement procedures, and the need to provide secure fallback methods when a key is lost. Organizations may issue multiple authenticators or combine hardware devices with carefully controlled recovery processes.
Passkeys represent a newer passwordless authentication method based on FIDO standards and public-key cryptography. A unique credential is created for each service, and the user’s private key remains protected by the device or credential provider rather than being sent to the website. The device may require a fingerprint, face scan, PIN, or other local unlock method before using the passkey. FIDO states that every passkey is bound to the service and that biometric information, when used, remains on the user’s device. Passkeys can therefore reduce password reuse, credential stuffing, and phishing while also simplifying the login experience for many users.
Authentication Factors and Multi-Factor Authentication
Authentication factors describe the different categories of evidence a person can provide when proving control of an account. The three most commonly used categories are something you know, something you have, and something you are. Passwords and PINs belong to the knowledge category, while smartphones, authentication tokens, smart cards, and security keys belong to the possession category. Fingerprints and facial recognition represent inherence or biometric characteristics. OWASP also discusses contextual categories such as somewhere you are and something you do, including location and behavioral patterns, although the first three factors remain the most common for web authentication.
Multi-factor authentication requires evidence from more than one independent factor category. A password plus a security key is MFA because the attacker would generally need both the secret knowledge and the physical authenticator. A password followed by another password is not MFA because compromising the user’s knowledge factor could potentially compromise both credentials. This distinction explains why simply adding extra questions does not necessarily create strong authentication. OWASP also notes that security questions are no longer recognized as an acceptable authentication factor under current NIST guidance because their answers may be guessable or discoverable. True MFA aims to make one stolen credential insufficient for account takeover.
MFA provides particularly strong value against password-focused attacks such as credential stuffing, password spraying, and automated guessing. If attackers obtain a valid password from another breach, they still need the second independent factor before they can successfully log in. OWASP describes MFA as a critical defense against common password-related account compromises and recommends requiring it for administrative and other highly privileged accounts. However, the security level depends on the factors selected. A security key or passkey can provide stronger protection against phishing than an SMS code that a victim may accidentally enter into a fraudulent website.
Organizations should also think carefully about MFA recovery and reset procedures. A company can deploy extremely strong MFA and then accidentally undermine it by allowing attackers to bypass that protection through weak help-desk verification or insecure recovery questions. Users inevitably lose phones, replace devices, forget credentials, and damage security keys, so recovery cannot simply be ignored. OWASP stresses that MFA reset processes themselves can become attractive targets and should be designed securely. High-risk accounts may require stronger recovery checks, multiple registered authenticators, recovery codes, administrative approval, or identity verification proportional to the potential consequences of account compromise.
Risk should determine how strongly MFA is enforced. A low-risk consumer service might offer optional MFA and encourage users to enable it, whereas financial, administrative, healthcare, cloud, or infrastructure accounts may justify mandatory stronger authentication. NIST’s current assurance framework requires two distinct authentication factors at AAL2 and says phishing-resistant authentication should be available, while AAL3 requires phishing-resistant cryptographic authentication. The goal is not simply adding as many prompts as possible. Effective multi-factor authentication selects independent factors that meaningfully increase security without creating so much friction that users develop unsafe workarounds.
Passwordless Authentication and Passkeys
Passwordless authentication allows users to sign in without entering a traditional password. The term covers several technologies, including passkeys, hardware security keys, certificates, and certain email- or device-based flows. The primary motivation is straightforward: passwords create recurring security and usability problems because people forget them, reuse them, choose weak values, and disclose them through phishing. Removing the shared password can eliminate entire categories of attack, although the security of a passwordless implementation still depends on the specific technology and its recovery process. Simply replacing a password with an easily phished magic code does not automatically create phishing-resistant authentication.
Passkeys are currently one of the most significant passwordless technologies because they use asymmetric cryptography. During registration, a cryptographic key pair is created for the account. The public key can be stored by the service, while the private key remains protected by the user’s device or credential provider. During sign-in, the service sends a challenge that must be cryptographically signed by the appropriate private key. FIDO explains that passkeys are unique to each service and are bound to that service’s domain, helping prevent a fraudulent website from using the credential successfully.
Passkeys can be either synchronized across a user’s trusted devices or bound to a particular authenticator, depending on implementation and security requirements. Synced passkeys improve convenience because someone can sign in from multiple devices without manually creating a new credential for each one. Device-bound credentials can provide additional control in environments where organizations need stronger restrictions around credential export. FIDO notes that both synced and device-bound approaches have legitimate use cases and that organizations should select deployment models according to their assurance requirements. Enterprise deployments may therefore look different from passkey use on ordinary consumer websites.
One of the major benefits of passkeys is phishing resistance. Traditional passwords and one-time codes can be typed into convincing fake websites, allowing attackers to steal or relay the information. FIDO authentication instead binds the credential to the legitimate relying party, making the authentication secret unusable on an attacker’s unrelated phishing domain. This does not mean every account using passkeys becomes impossible to compromise. Weak account recovery, compromised devices, malicious software, social engineering of support teams, and insecure fallback login methods can still undermine strong primary authentication if organizations fail to secure the entire account lifecycle.
Passkey deployment should therefore include registration, recovery, device replacement, cross-device sign-in, fallback methods, and account-management security rather than focusing only on the initial login button. FIDO’s guidance on preventing phishing specifically warns that leaving phishable fallback or recovery methods available can allow attackers to bypass stronger passkey authentication. Organizations moving toward passwordless login can begin by allowing passkeys alongside existing authentication, gather adoption data, improve recovery processes, and eventually reduce dependence on passwords where appropriate. The long-term value comes from redesigning authentication around phishing-resistant credentials rather than merely adding another sign-in option.
Authentication vs Authorization, SSO and Identity Verification
Authentication and authorization are closely connected but answer different security questions. Authentication asks, “Who are you?”, while authorization asks, “What are you allowed to do?” A user might successfully authenticate to an employee portal but still lack permission to view payroll records belonging to other employees. Authentication establishes the user’s identity or account context, while authorization rules determine which resources and actions that identity can access. Keeping these functions conceptually separate is important because strong authentication cannot compensate for weak permissions. An application can verify the correct user perfectly and still expose sensitive data if its authorization logic allows that user to access inappropriate resources.
Identity verification or identity proofing is different again. It attempts to establish whether the person creating or recovering an account corresponds to a claimed real-world identity. This may involve government documents, database checks, in-person verification, biometrics, or other evidence depending on the required assurance level. Authentication then verifies future control of the credentials bound to that account. NIST’s digital identity framework treats identity proofing and authentication as separate assurance considerations because a service may need strong authentication without necessarily knowing the user’s civil identity. Understanding these distinctions helps organizations avoid asking users for unnecessary personal information merely because authentication is required.
Single sign-on, commonly abbreviated SSO, allows users to authenticate through a centralized identity provider and then access multiple connected applications without signing in separately to each service. Enterprises frequently use SSO so employees can access collaboration software, cloud applications, internal tools, and other systems through one managed identity. This can improve usability and make account administration more consistent, particularly when an employee joins or leaves the organization. However, centralization also makes the identity provider highly important because compromising one SSO account can potentially provide access to several connected applications. Strong MFA and careful session management are therefore especially valuable around centralized identity systems.
OpenID Connect is one common protocol used for federated authentication and SSO on modern applications. OWASP explains that OpenID Connect, or OIDC, is an identity layer built on OAuth and is intended for authentication, whereas OAuth itself is primarily an authorization framework for delegated API access. This distinction is frequently misunderstood because many “Sign in with…” experiences involve both technologies. Developers should use established protocols and well-maintained libraries instead of designing custom authentication or token systems without a strong reason. Mature standards reduce the number of security decisions application teams must invent independently.
Federated authentication can also reduce the number of passwords users maintain because authentication responsibility is delegated to a trusted identity provider. A company may allow employees to access several SaaS tools through its corporate identity platform, or a consumer website may offer authentication through another trusted account provider. However, federation requires careful validation of tokens, issuer information, audiences, expiration, redirect behavior, and other protocol details. OWASP recommends correctly validating OpenID Connect ID tokens and relying on established libraries and provider metadata. Whether authentication is local or federated, organizations should understand where trust begins, which system verifies the user, and how authorization is applied afterward.
Common User Authentication Threats
Credential stuffing is one of the most common threats to password-based authentication. Attackers obtain username and password combinations from one breach and automatically test them against many unrelated services, relying on widespread password reuse. A password can therefore be extremely complex and still fail to protect an account if the user has reused it on another compromised website. Multi-factor authentication reduces the effectiveness of these attacks because the stolen password alone is insufficient. Passkeys address the problem more fundamentally by creating unique cryptographic credentials for individual services, eliminating conventional password reuse across websites.
Password spraying and brute-force attacks involve guessing credentials rather than obtaining them directly from another breach. Brute force may involve many guesses against one account, while password spraying often tries a smaller number of common passwords against many accounts to avoid obvious lockouts. Authentication systems can reduce these attacks through rate limiting, progressive delays, appropriate lockout controls, MFA, password blocklists, and monitoring. OWASP recommends login throttling and carefully designed lockout defenses to limit automated guessing. Organizations should monitor failed authentication patterns because attacks can be distributed across multiple addresses and may not resemble simple repeated guessing from one computer.
Phishing attacks attempt to trick users into giving authentication information to an attacker. A fraudulent website may imitate a legitimate login page closely enough that a victim enters a password and one-time code without realizing anything is wrong. OTP-based MFA improves security against some attacks but does not automatically stop sophisticated real-time phishing because attackers can relay the temporary code immediately. NIST specifically states that manually entered OTP outputs are not phishing-resistant. Passkeys and FIDO security keys provide stronger protection because their cryptographic responses are bound to the legitimate service instead of relying on users to visually identify fake domains.
Session hijacking occurs after successful authentication rather than by directly stealing the original credentials. If an attacker obtains a valid session token, the application may treat the attacker as though they were the authenticated user. OWASP warns that disclosure, prediction, fixation, or theft of session identifiers can result in session hijacking and impersonation. Applications should therefore protect session cookies through secure transport, appropriate browser attributes, strong random identifiers, expiration, rotation, and server-side validation. Authentication security should always include the authenticated session because a perfect login mechanism provides limited protection if the resulting session can be easily stolen.
Account recovery is another major attack surface. Attackers may deliberately avoid the normal login process and instead exploit password-reset workflows, weak help-desk procedures, compromised email accounts, insecure recovery questions, or poorly protected backup factors. The recovery mechanism should not offer significantly weaker assurance than ordinary authentication because it effectively provides another route into the account. OWASP emphasizes that account recovery and MFA reset procedures need strong security controls. Organizations adopting advanced authentication technologies should therefore review every fallback path, including lost-device recovery, email changes, phone-number replacement, administrative resets, and emergency access.
User Authentication Best Practices
One of the most important best practices is to use MFA or phishing-resistant authentication according to account risk. Administrative accounts, cloud consoles, financial systems, sensitive customer information, and other high-value resources deserve stronger controls than low-risk public services. OWASP recommends MFA wherever practical and specifically calls for it on privileged accounts. NIST’s current AAL2 guidance requires two distinct authentication factors and requires services at that level to offer a phishing-resistant option, while AAL3 requires phishing-resistant cryptographic authentication. Where passkeys or FIDO security keys are practical, they can provide stronger protection against phishing than manually entered codes.
Password policies should emphasize length and resistance to known compromised passwords instead of complicated composition requirements. NIST’s current guidance requires passwords used as a single authentication factor to be at least 15 characters, while passwords used only within MFA can be shorter but must contain at least eight characters. NIST also says verifiers should block commonly used, expected, and compromised passwords rather than requiring arbitrary combinations of uppercase letters, numbers, and symbols. OWASP similarly advises against routine periodic password changes when no compromise has occurred and recommends allowing long passphrases, password-manager use, and paste functionality.
Protect authentication secrets both in transit and at rest. Login pages and authenticated application traffic should use TLS, while passwords should be stored through appropriate password-hashing mechanisms rather than plaintext or reversible encryption. Developers should use mature authentication frameworks and trusted libraries rather than creating custom cryptographic routines. Sensitive internal administrative accounts should also be separated appropriately from public authentication interfaces where possible. OWASP recommends strong transport protection, centralized authentication solutions, secure credential storage, and protecting sensitive accounts from inappropriate front-end exposure. Good authentication security comes from the entire implementation rather than merely choosing a strong login factor.
Design secure recovery, reauthentication, and session-management processes. Require additional verification before changing passwords, recovery email addresses, MFA configuration, or other high-impact account settings. Sessions should use unpredictable identifiers and should be invalidated appropriately on logout or after significant credential changes. OWASP also recommends rotating tokens after important authentication events and requiring reauthentication for sensitive operations. Users should have practical ways to recover access without creating an easy bypass for attackers. Providing multiple registered authenticators before an emergency occurs is often safer than relying on one weak fallback mechanism.
Finally, log and monitor authentication activity so attacks can be detected rather than merely blocked one login at a time. Useful signals include repeated failed logins, unusual password-reset activity, suspicious MFA changes, unexpected geographic patterns, account lockouts, privileged login attempts, and large-scale credential testing. OWASP recommends recording authentication failures and reviewing account lockouts and password failures for signs of attack. Monitoring systems should prioritize meaningful anomalies without collecting unnecessary sensitive data. Security teams should also test authentication flows regularly because changes to applications, identity providers, mobile clients, APIs, and recovery processes can introduce vulnerabilities even when the original login design was secure.
How to Choose the Right Authentication Method
The right authentication method depends first on the consequences of unauthorized access. A low-risk community account may not justify the same controls as a system containing medical records, financial transactions, infrastructure credentials, or enterprise administrator privileges. Organizations should classify applications according to data sensitivity, transaction risk, user population, regulatory requirements, and potential impact of account compromise. NIST’s assurance framework provides a useful model by mapping increasing risk to stronger Authentication Assurance Levels. The objective is to make authentication proportionate to the threat rather than adding unnecessary friction everywhere or applying weak controls to critical systems.
User experience should also influence the design because security mechanisms that are consistently confusing can lead to support costs and unsafe workarounds. Employees may write down complicated rotating passwords, users may abandon accounts when recovery is difficult, and excessive prompts can produce MFA fatigue. Password managers, passkeys, platform biometrics, and SSO can sometimes improve security and usability simultaneously. FIDO notes that passkeys are designed to simplify sign-in while preventing credential reuse and providing phishing resistance. Strong authentication should aim to make the secure behavior easier rather than requiring users to perform complicated security rituals every time they access a service.
Consider the devices and environments where authentication will occur. A workforce using managed laptops can support different technologies from customers accessing a service across thousands of personal phones and browsers. Hardware security keys may be appropriate for privileged enterprise staff but expensive to distribute to every low-risk consumer. Passkeys can provide broad compatibility across modern platforms, while specialized environments may require smart cards, client certificates, or device-bound credentials. Accessibility requirements should also be included so users are not excluded because they cannot use a particular biometric sensor, phone, or physical interaction method.
Integration requirements matter for organizations managing many applications. Centralized identity platforms and single sign-on authentication can reduce the number of separate credentials employees need while giving administrators a consistent place to enforce MFA, disable accounts, and monitor access. OpenID Connect and other established federation technologies should be preferred over proprietary authentication methods when they meet the business requirement. OWASP recommends using OIDC for authentication and SSO while treating OAuth as authorization for APIs. Centralization can improve management, but the identity provider itself becomes highly sensitive and should therefore receive particularly strong protection.
Finally, plan for future migration rather than treating authentication as a permanent one-time configuration. Threats change, browsers and operating systems evolve, regulations develop, and authentication methods that were once considered strong can become outdated. Organizations heavily dependent on passwords and SMS codes can begin introducing stronger alternatives such as TOTP, security keys, or passkeys according to their risk and user base. Measure enrollment rates, failed logins, recovery requests, help-desk load, phishing incidents, and authentication completion rates to understand whether the design is working. The best user authentication system combines appropriate assurance, strong security, manageable recovery, broad accessibility, and a login experience users can successfully complete.
FAQs About User Authentication
What is user authentication?
User authentication is the process of verifying that someone trying to access an account or system controls credentials associated with that identity. Common credentials include passwords, passkeys, security keys, OTPs, and biometrics.
What are the three main authentication factors?
The three most common factors are something you know, something you have, and something you are. Examples are passwords, security keys, and fingerprints.
What is multi-factor authentication?
MFA requires two or more different authentication factors before granting access. A password combined with a security key is an example.
Is 2FA the same as MFA?
Two-factor authentication is a type of MFA that specifically uses two factors. MFA can involve two or more independent factors.
What is the safest authentication method?
There is no single method for every situation, but phishing-resistant cryptographic authentication such as properly implemented passkeys and FIDO security keys provides strong protection against common credential attacks.
Are SMS codes secure?
SMS codes can improve security compared with passwords alone, but they are not phishing-resistant and have other weaknesses. Stronger options such as passkeys or hardware security keys may be preferable for high-risk accounts.
What is passwordless authentication?
Passwordless authentication verifies users without requiring a traditional password. Passkeys, FIDO security keys, and certain certificate-based systems are common examples.
What is a passkey?
A passkey is a FIDO credential that uses public-key cryptography instead of a shared password. It is designed to provide convenient and phishing-resistant sign-in.
What is the difference between authentication and authorization?
Authentication verifies who the user is, while authorization determines what that authenticated user is permitted to access or do.
Why is authentication important?
Authentication helps prevent unauthorized users from accessing accounts, sensitive information, applications, and administrative functions. Strong authentication reduces the risk of account takeover and related security incidents.
