FIDO2 WebAuthn: The Complete Guide to Passwordless Authentication

Passwords have dominated digital authentication for decades, yet they remain fundamentally flawed. Data breaches expose billions of credentials annually, costing organizations millions in damages. Phishing attacks exploit password weaknesses with alarming success rates. Users struggle with password fatigue, creating weak or reused credentials across multiple accounts.

FIDO2 and WebAuthn represent a paradigm shift in authentication technology. These standards enable passwordless login using cryptographic keys instead of shared secrets. Public key cryptography ensures that even if servers are breached, attackers gain nothing usable. The authentication process binds credentials to specific domains, making phishing technically impossible.

Major technology companies have enthusiastically embraced these standards. Google, Microsoft, Apple, and others now support FIDO2 WebAuthn across their platforms. Financial institutions, healthcare providers, and government agencies are rapidly adopting passwordless authentication. This widespread support signals a fundamental transformation in how we approach digital identity.

Understanding FIDO2 WebAuthn is essential for modern security professionals and developers. This guide provides comprehensive coverage of technical concepts, practical implementation strategies, and real-world applications. 

What Is FIDO2?

FIDO2 represents the second major specification from the FIDO Alliance. It enables passwordless authentication across websites and applications via public-key cryptography. This standard provides a framework for strong, phishing-resistant authentication that does not rely on passwords.

The FIDO2 framework consists of these primary components:

• WebAuthn (Web Authentication API): This browser-based API enables websites to integrate passwordless authentication directly into web applications.
• CTAP (Client to Authenticator Protocol): This protocol enables communication between client devices and external authenticators, such as security keys.
• Public key cryptography foundation: FIDO2 uses asymmetric cryptography, where private keys never leave the authenticator device.
• FIDO Alliance certification: Products must meet rigorous security and interoperability standards to achieve FIDO2 certification.
• Cross-platform compatibility:  FIDO2 works seamlessly across different operating systems, browsers, and device types.

What Is WebAuthn?

WebAuthn is a web standard developed by the W3C and FIDO Alliance. It provides the browser API that enables passwordless authentication on websites. WebAuthn allows servers to register and authenticate users using public key credentials instead of passwords.

Key characteristics of WebAuthn include:

• Browser-native implementation: Modern browsers such as Chrome, Firefox, Safari, and Edge support WebAuthn natively, without plugins.
• JavaScript API access: Developers interact with WebAuthn through standardized JavaScript methods for credential creation and authentication.
• Relying party integration: Websites (relying parties) implement WebAuthn to enable passwordless login for their users.
• Cryptographic credential binding: WebAuthn credentials are bound to specific domains, preventing credential phishing across sites.
• Biometric and PIN support: User verification can leverage fingerprints, facial recognition, or device PINs for authentication.

FIDO2 vs WebAuthn: Understanding the Relationship

Many people use FIDO2 and WebAuthn interchangeably, but they represent different components. FIDO2 is the umbrella specification that encompasses both WebAuthn and CTAP protocols. Understanding their relationship clarifies how passwordless authentication works end-to-end.

The distinction becomes clear when examining components:

• FIDO2 is the complete framework: It includes all protocols and specifications needed for passwordless authentication across platforms.
• WebAuthn operates on the client side: It handles browser-based authentication interactions between websites and authenticators.
• CTAP connects external authenticators: This protocol enables communication between devices like YubiKeys and the client platform.
• Together, they enable passwordless flows: WebAuthn handles web integration, while CTAP manages communication with external authenticators.
• Implementation requires both components: Developers use WebAuthn APIs while CTAP works transparently in the background for external authenticators.

Why Passwords Are Fundamentally Broken

Traditional password-based authentication suffers from inherent security and usability flaws. Understanding these weaknesses helps explain why passwordless approaches like FIDO2 WebAuthn have gained momentum. Let's examine the critical problems that make passwords inadequate for modern security needs.

1. Shared Secrets Are Vulnerable to Theft

Passwords function as shared secrets stored on both the client and server sides. This architecture creates numerous points where attackers can intercept or steal credentials. Database breaches expose millions of passwords regularly, forcing users to change credentials across multiple services.

Server-side storage means organizations become attractive targets for sophisticated attacks. Even with hashing and salting, determined attackers can crack weak passwords offline. The fundamental problem remains that servers hold something valuable that can be stolen.

2. Phishing Attacks Are Highly Effective

Phishing exploits users' inability to distinguish legitimate login pages from fraudulent ones. Attackers create convincing replicas of banking, email, or corporate login screens. Users entering credentials on these fake pages are effectively handing their passwords to criminals.

Security awareness training helps, but cannot eliminate human error. Even security-conscious users fall victim to sophisticated phishing campaigns using urgency tactics. Password-based authentication provides no technical mechanism to fundamentally prevent these attacks.

3. Credential Stuffing and Password Reuse

Users manage dozens of online accounts, making it practically impossible to remember unique passwords. Research shows that over half of people reuse passwords across multiple services. When one service suffers a breach, attackers test those credentials everywhere.

Credential stuffing attacks automate this process at a massive scale using botnets. Attackers obtain billions of username and password combinations from various breaches. They successfully test these combinations across banking, retail, and enterprise services.

4. Weak Password Creation

Password complexity requirements often backfire by encouraging predictable patterns. Users create passwords like "Password123!" that technically meet requirements but remain easily guessable. Dictionary attacks combined with common substitution patterns quickly crack these passwords.

Length and randomness requirements frustrate users without significantly improving security. People write down complex passwords, store them insecurely, or use predictable patterns. The cognitive burden of managing strong passwords exceeds most users' capacity.

5. High Management Overhead

Password management creates significant IT support costs for organizations. Helpdesk teams spend substantial time resetting employees' forgotten passwords. Some estimates suggest that password resets cost enterprises $70 per incident when staff time is factored in.

Users also waste productive time dealing with password-related issues. Forgotten passwords interrupt workflows and create friction in user experiences. Organizations implement password managers to address this, adding another layer of complexity.

6. MFA Fatigue and Bypass Techniques

Multi-factor authentication adds security but introduces usability challenges and new attack vectors. Users experience notification fatigue from constant MFA prompts throughout their workday. This fatigue makes users more likely to approve fraudulent authentication requests carelessly.

Sophisticated attackers exploit MFA fatigue through prompt bombing techniques. They trigger dozens of MFA requests, hoping users approve one to stop notifications. SMS-based MFA remains vulnerable to SIM swapping and interception attacks.

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How FIDO2 WebAuthn Works: Technical Architecture

FIDO2 WebAuthn relies on asymmetric cryptography to enable secure, passwordless authentication. The architecture separates credential creation (registration) from credential usage (authentication). Private keys remain secured on authenticator devices while public keys are stored on servers.

Step-by-Step: FIDO2 WebAuthn Registration Flow

Registration establishes a cryptographic relationship between the user, the authenticator, and the relying party. This one-time process creates unique key pairs specific to each service. Understanding registration flow helps developers implement WebAuthn correctly.

Step 1: User Initiates Registration

The user navigates to a website and chooses to register using passwordless authentication. The website presents options to create credentials using biometrics, security keys, or platform authenticators.

Step 2: Relying Party Generates Challenge

The server generates a unique, random challenge to ensure registration freshness. This challenge prevents replay attacks by requiring cryptographic proof of the current session.

Step 3: WebAuthn API Invoked

The website calls navigator.credentials.create() to start the credential creation process. The browser displays a prompt asking the user to interact with their authenticator.

Step 4: User Verification

The authenticator requests user verification through a biometric scan, PIN entry, or gesture. This step confirms the user's identity and authorizes the generation of a key pair.

Step 5: Key Pair Generation

The authenticator generates a new public-private key pair unique to this relying party. The private key remains permanently secured in the authenticator's protected storage.

Step 6: Public Key and Attestation Returned

The authenticator returns the public key along with optional attestation data to the browser. An attestation provides cryptographic proof of the authenticator's make and model.

Step 7: Server Stores Public Key

The server validates the attestation and stores the public key linked to the user account. Registration completes successfully, enabling future passwordless authentication for this user.

Step-by-Step: FIDO2 WebAuthn Authentication Flow

Authentication uses the previously registered credentials to verify user identity. The process leverages the private key stored on the authenticator to prove possession of it. Each authentication generates unique cryptographic signatures, preventing replay attacks.

Step 1: User Initiates Login

The user navigates to the login page and enters their username or identifier. The website recognizes that this user has registered FIDO2 credentials available.

Step 2: Server Generates Authentication Challenge

The server creates a fresh, random challenge specific to this authentication attempt. The user's private key will cryptographically sign this challenge.

Step 3: WebAuthn API Called

The website invokes navigator.credentials.get() to request authentication from available credentials. The browser prompts the user to use their registered authenticator.

Step 4: Credential Selection

If multiple credentials exist, the authenticator presents them for the user to select. The user chooses which credential to use for this authentication.

Step 5: User Verification

The authenticator again requires user verification via biometrics, PIN, or gesture. This ensures the legitimate user is present and authorizing the authentication.

Step 6: Private Key Signs Challenge

The authenticator uses the stored private key to sign the challenge cryptographically. This signature proves possession of the credential without revealing the private key.

Step 7: Assertion Returned to Server

The signed challenge (assertion) is returned to the browser and forwarded to the server. The assertion includes the signature and metadata about the authentication.

Step 8: Server Verifies Signature

The server validates the signature using the user's stored public key. Successful verification confirms the user's identity and grants access to the account.

Benefits of FIDO2 WebAuthn Authentication

Organizations adopting FIDO2 WebAuthn experience significant security and operational improvements. Passwordless authentication addresses fundamental vulnerabilities while simultaneously enhancing the user experience. Let's explore the key advantages driving widespread adoption across industries.

1. Eliminates Phishing Attacks

FIDO2 WebAuthn credentials are cryptographically bound to specific domain origins. Attackers cannot use fraudulent websites to capture credentials even if users attempt to log in. The browser validates the domain origin before automatically allowing credential usage. This technical safeguard makes traditional phishing attacks completely ineffective against FIDO2 authentication.

2. Prevents Credential Theft and Server Breaches

Servers store only public keys, which provide no value to attackers if stolen. Private keys never leave the user's authenticator device under any circumstances. Even if attackers compromise the entire server database, they gain nothing usable. This architecture eliminates the most common and damaging attack vector in cybersecurity.

3. Superior User Experience

Users authenticate in seconds with simple biometric scans or a simple touch of a security key. No need to remember complex passwords or wait for SMS codes. The authentication process becomes faster and more convenient than traditional methods. Reduced friction leads to higher user satisfaction and adoption rates.

4. Resistant to Sophisticated Attacks

FIDO2 inherently prevents credential stuffing, brute-force, and man-in-the-middle attacks. Each credential is unique per service, eliminating the vulnerability of password reuse. The cryptographic nature of authentication makes interception and replay attacks technically impossible. Even advanced persistent threats find FIDO2 authentication extremely difficult to compromise.

5. Reduces IT Support Costs

Eliminating passwords removes the primary driver of helpdesk support requests. Users never experience password lockouts, forgotten credentials, or reset requirements. IT teams redirect resources from password management to higher-value security initiatives. Organizations report a 50-70% reduction in authentication-related support tickets after implementing passwordless solutions.

6. Privacy Preserving

FIDO2 authentication does not allow tracking users across different services or websites. Each credential contains no personally identifiable information about the user. Biometric data remains on the local device and is never transmitted to servers. This privacy-first approach aligns with GDPR and other data protection regulations.

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Real-World Use Cases for FIDO2 WebAuthn

FIDO2 WebAuthn delivers value across diverse industries facing different security challenges. Organizations deploy passwordless authentication to protect sensitive data while improving user workflows. These use cases demonstrate practical applications and benefits achieved in production environments.

1. Banking and Financial Services

Financial institutions face constant attacks targeting customer accounts and sensitive transaction data. FIDO2 WebAuthn eliminates credential-based attacks while meeting regulatory compliance requirements. Banks report significant reductions in account takeover incidents after implementing passwordless authentication. Customers appreciate faster, more convenient access to banking services without compromising security.

2. E-Commerce and Retail

Online retailers need frictionless checkout processes to maximize conversion rates. FIDO2 WebAuthn enables one-touch authentication, significantly reducing cart abandonment. Customers complete purchases faster without entering passwords or waiting for OTPs. Retailers also benefit from reduced fraud losses and fewer account compromise incidents.

3. Enterprise and Workforce Authentication

Companies implement FIDO2 WebAuthn for employee access to corporate resources and applications. Passwordless authentication improves productivity by eliminating password-related delays and lockouts. IT teams reduce helpdesk burden while strengthening the organization's security posture. Remote workers authenticate seamlessly across devices without VPN or password complications.

4. Healthcare and Medical Systems

Healthcare providers protect patient records while enabling efficient clinician workflows. FIDO2 WebAuthn enables doctors and nurses to access electronic health records quickly. The technology meets HIPAA compliance requirements while preventing unauthorized access attempts. Passwordless authentication reduces friction that often leads to security workarounds in clinical settings.

5. Government and Public Sector

Government agencies handle sensitive citizen data requiring the highest security standards. FIDO2 WebAuthn provides phishing-resistant authentication meeting federal identity requirements. Public sector organizations use passwordless authentication for employee access and citizen services. The technology supports secure remote work initiatives across government departments.

6. SaaS Applications and Cloud Services

Software-as-a-service providers integrate FIDO2 WebAuthn to protect customer accounts and data. Passwordless authentication differentiates SaaS offerings by providing superior security and convenience. Cloud platforms enable customers to secure their environments without relying on passwords. Multi-tenant architectures benefit from cryptographic isolation of authentication per customer organization.

7. High-Security and Privileged Access

Organizations use FIDO2 WebAuthn for privileged access management and administrative accounts. Security-critical systems require the strongest authentication possible to prevent breaches. Passwordless authentication protects against targeted attacks on high-value administrator credentials. Compliance frameworks increasingly recommend or require phishing-resistant authentication for privileged access.

How to Implement FIDO2 WebAuthn (Developer Guide)

Implementing FIDO2 WebAuthn requires careful planning and technical execution across the frontend and backend. Developers must understand the WebAuthn API, cryptographic validation, and user experience considerations. This guide provides a structured approach to deploying a successful passwordless authentication solution.

1. Plan Your Implementation and Choose Tools

Begin by carefully assessing your application architecture and authentication requirements. Select appropriate FIDO2 libraries or SDKs compatible with your technology stack. Popular options include Yubico's libraries, Auth0's WebAuthn implementation, or open-source alternatives. Determine whether you need platform authenticators, roaming authenticators, or both for flexibility.

2. Configure Server-Side Relying Party

Set up your relying party server to handle WebAuthn credential registration and authentication. Implement endpoints for generating challenges, validating attestations, and verifying assertions. Ensure proper origin validation to prevent subdomain and related-domain attacks. Store public keys securely in your user database with appropriate indexing.

3. Implement Client-Side WebAuthn API

Integrate the navigator.credentials.create() and navigator.credentials.get() methods into your frontend. Handle browser compatibility gracefully by detecting WebAuthn support before offering passwordless options. Implement proper error handling for scenarios such as timeouts, cancellations, or authenticator issues. Provide clear user instructions and feedback throughout the authentication process.

4. Configure User Verification and Credential Management

Define your user verification requirements based on security needs and user experience goals. Choose between platform, cross-platform, or discouraged user verification appropriately. Implement credential discovery to allow users to manage their registered authenticators. Provide users with the option to register multiple authenticators for redundancy.

5. Design Fallback and Recovery Mechanisms

Plan account recovery processes for scenarios where users lose access to authenticators. Implement backup authentication methods or recovery codes for regaining account access. Consider attestation requirements carefully, balancing security needs against privacy concerns. Ensure your fallback mechanisms don't reintroduce the vulnerabilities that passwordless authentication eliminates.

6. Test Thoroughly Across Platforms

Verify WebAuthn functionality across different browsers, operating systems, and authenticator types. Test both registration and authentication flows with platform authenticators and security keys. Validate error handling scenarios, including network failures, timeouts, and user cancellations. Ensure mobile implementations work correctly with both built-in and external authenticators.

7. Deploy, Monitor, and Optimize

Roll out FIDO2 WebAuthn gradually to users, monitoring adoption and identifying issues. Collect telemetry on authentication success rates, timing, and error types. Provide clear documentation and support channels for users encountering difficulties. Continuously optimize the user experience based on real-world usage patterns and feedback.

Challenges for FIDO2 WebAuthn Implementation & How to Overcome

Despite significant advantages, implementing FIDO2 WebAuthn presents several challenges. Organizations must carefully address technical, operational, and user experience considerations. Understanding common obstacles and solutions helps ensure a successful deployment of passwordless authentication.

1. Legacy System Integration

Problem Statement

Many organizations operate legacy authentication systems built around password-based workflows. These systems lack native FIDO2 support and require significant modification efforts.

Integration complexity increases when dealing with mainframes, older databases, or custom authentication layers. Organizations struggle to justify the development effort required for modernizing legacy infrastructure.

How to Overcome This Challenge

• Implement authentication abstraction layers that translate FIDO2 tokens into legacy-compatible formats.
• Deploy identity federation protocols like SAML or OpenID Connect between modern and legacy systems.
• Prioritize high-value applications for initial FIDO2 implementation while gradually migrating legacy systems.
• Consider third-party identity and access management platforms that bridge modern passwordless and legacy password-based authentication.
• Use reverse proxy solutions that add FIDO2 authentication in front of legacy applications.

2. Device and Browser Compatibility

Problem Statement

Although WebAuthn enjoys broad support, older browsers and devices lack FIDO2 capabilities. Users on corporate-managed devices may face restrictions preventing authenticator registration.

Mobile implementations vary across iOS and Android, resulting in inconsistent experiences. Organizations must support diverse user environments while consistently maintaining security standards.

How to Overcome This Challenge

• Implement feature detection to degrade to an alternative authentication method in unsupported environments gracefully.
• Provide clear guidance on supported browsers and devices before users attempt registration.
• Deploy fallback authentication methods that maintain acceptable security for non-compliant devices.
• Consider progressive enhancement strategies that offer passwordless options where supported.
• Work with IT departments to ensure corporate device policies allow the use of authenticators.

3. Account Recovery Complexity

Problem Statement

Users who lose access to their registered authenticators face account lockout. Traditional password reset flows don't apply to passwordless authentication systems. Organizations must balance security with account recovery accessibility for legitimate users.

Overly complex recovery processes frustrate users while weak processes compromise security.

How to Overcome This Challenge

• Encourage users to register multiple authenticators during initial setup for redundancy.
• Implement secure recovery codes stored safely by users as backup access methods.
• Provide authenticated device recognition that allows recovery from previously used devices.
• Offer identity verification processes through support channels for high-value accounts.
• Consider risk-based authentication that allows temporary access for account recovery scenarios.

4. Passkey Sync Concerns

Problem Statement

Platform passkey sync across devices introduces new security considerations for organizations. Some enterprise security policies prohibit synchronizing credentials with cloud services. Users benefit from the convenience of passkey sync, but organizations worry about cloud storage risks. Balancing user experience with enterprise security requirements creates policy challenges.

How to Overcome This Challenge

• Educate stakeholders on passkey sync security architecture and end-to-end encryption protections.
• Implement policies allowing sync for consumer applications while restricting it for sensitive enterprise systems.
• Provide organization-managed authenticators for high-security scenarios requiring local storage only.
• Deploy mobile device management solutions that appropriately control passkey sync settings.
• Offer users a choice between synced passkeys and device-bound credentials, depending on their needs.

5. Privacy and Data Handling

Problem Statement

Attestation data reveals the make and model of authenticators, raising privacy concerns. Organizations must determine appropriate attestation verification levels that balance security and privacy.

Biometric data handling requires careful consideration of privacy regulations and user trust. Users worry about the storage of biometric information and its potential misuse by service providers.

How to Overcome This Challenge

• Use indirect attestation or no attestation for consumer applications, prioritizing privacy.
• Clearly communicate that biometric data never leaves the user's device during authentication.
• Implement transparent privacy policies that explain exactly which authentication data is collected.
• Comply with GDPR, CCPA, and other privacy regulations in credential and attestation handling.
• Allow users to understand and control what authenticator information is shared with services.

Best Practices for FIDO2 WebAuthn Implementation

Following established best practices ensures successful FIDO2 WebAuthn deployment and user adoption. These recommendations draw from real-world implementations across various industries and use cases. Applying these principles helps organizations maximize security benefits while delivering excellent user experiences.

1. Implement Strong Security Fundamentals

Always validate origin and relying party ID rigorously to prevent domain confusion attacks. Use cryptographically secure random number generation for challenges to avoid predictability. Verify attestation statements in accordance with your organization's risk tolerance and compliance requirements. Implement rate limiting and monitoring to detect and prevent abuse attempts early.

2. Support Multiple Authenticators and Recovery Options

Allow users to register several authenticators, including platform, cross-platform, and security keys. Provide clear guidance on authenticator selection based on user scenarios and devices. Implement backup authentication methods that maintain security without reintroducing password vulnerabilities. Enable users to easily manage their authenticators through intuitive credential management interfaces.

3. Optimize User Verification and Attestation

Choose user verification requirements carefully based on your application's security needs. Consider using preferred user verification rather than requiring it to maximize compatibility. Implement attestation verification only when specific authenticator trust requirements exist at the organizational level. Balance security requirements against user experience impact through thoughtful policy configuration.

4. Design Exceptional User Experience

Provide clear, contextual guidance throughout the user registration and authentication processes. Implement progressive disclosure showing advanced options only when users need them. Design error messages that help users understand issues and take corrective action. Test authentication flows extensively with real users across diverse devices and scenarios.

5. Manage Credential Lifecycle Effectively

Implement secure credential discovery so users can identify which authenticators they've registered. Provide straightforward processes for revoking lost or compromised authenticators from user accounts. Monitor credential usage patterns to identify potentially compromised credentials requiring investigation. Maintain audit logs of credential registration, usage, and revocation for compliance purposes.

6. Implement Progressive Deployment and Stay Current

Roll out FIDO2 WebAuthn incrementally, starting with low-risk users or applications. Monitor adoption rates, authentication success metrics, and user feedback during rollout phases. Stay informed about WebAuthn specification updates and browser implementation changes affecting functionality. Regularly update dependencies and libraries to benefit from security improvements and new features.

How OLOID Simplifies FIDO2 WebAuthn Implementation

FIDO2 WebAuthn has set a strong foundation for passwordless authentication by replacing shared secrets with public key cryptography. It significantly reduces phishing risk, credential reuse, and password-related attacks while improving login security. For many organizations, FIDO2 represents an important shift away from legacy authentication models that rely heavily on passwords.

However, implementing FIDO2 in real-world environments is not always straightforward. Hardware keys, device dependencies, and user enrollment challenges can limit adoption, particularly for frontline and distributed workforces. When passwordless authentication is difficult to deploy or manage, its security benefits can remain underutilized.

OLOID, a passwordless authentication platform, provides comprehensive FIDO2 WebAuthn support for phishing-resistant authentication. The platform leverages WebAuthn browser APIs and CTAP2 protocol to deliver strong authentication using biometrics or security keys. Organizations seamlessly integrate OLOID with existing SSO systems to provide modern, passwordless login experiences.

Key capabilities of OLOID's FIDO2 WebAuthn implementation include:

• Passwordless login functionality: Users access SSO systems like Okta and Entra ID without passwords using device-bound credentials.
• Phishing-resistant security: Passkeys remain secured on user devices, preventing credential theft, unlike traditional password-based authentication.
• Platform authenticator support: Built-in features like Windows Hello, Face ID, and fingerprint sensors work natively for seamless authentication.
• Roaming authenticator compatibility: External USB and NFC security keys provide users with cross-device authentication flexibility.
• Pre-configured FIDO standards: WebAuthn APIs and CTAP2 integration enable rapid deployment without extensive custom development efforts.
• Enterprise system integration: Organizations effortlessly connect passwordless authentication with existing identity infrastructure and application ecosystems.

If you want to see how OLOID can help you implement passwordless authentication beyond FIDO2, book a demo and explore how it works in action.

FAQs on FIDO2 WebAuthn

1. Is FIDO2 WebAuthn really phishing-resistant?

Yes, FIDO2 WebAuthn is inherently phishing-resistant due to its cryptographic architecture. Credentials are bound to specific domain origins and cannot function on fraudulent websites. Even if users attempt to authenticate on phishing sites, the browser prevents them from submitting credentials. This technical safeguard operates automatically without requiring user vigilance or judgment about site legitimacy.

2. Do I need to buy a security key to use FIDO2 WebAuthn?

No, most modern devices include built-in platform authenticators supporting FIDO2 WebAuthn authentication. Windows Hello, Touch ID, Face ID, and Android biometrics all function as FIDO2 authenticators. However, security keys offer additional benefits, such as cross-device compatibility and enhanced security. Many security-conscious users register both platform authenticators and external security keys for flexibility.

3. What are passkeys, and how do they relate to FIDO2?

Passkeys are a consumer-friendly implementation of FIDO2 credentials with cloud synchronization. They use the same underlying FIDO2 WebAuthn standards but sync automatically across devices. Major platforms like Apple, Google, and Microsoft support passkey sync through their ecosystems. Passkeys make FIDO2 more accessible to average users while maintaining strong security properties.

4. Can FIDO2 WebAuthn work without an internet connection?

Yes, FIDO2 WebAuthn authentication can function offline for cached credentials and local authentication. The cryptographic operations occur locally on the device without requiring server communication. However, initial registration and some attestation validations typically require internet connectivity initially. Once credentials are established, authentication can proceed offline depending on application architecture and caching.