What Is Passwordless Authentication?

Passwordless authentication is a method of verifying a user’s identity without requiring them to enter a password. It uses alternative methods such as biometric authentication, security keys, or one-time codes sent to the user’s email or phone. Passwordless authentication solutions help improve security and user experience by eliminating the need for users to remember and manage complex passwords.

Passwordless authentication relies on two core authentication factors as defined by most industry standards, like FIDO2 and NIST SP 800-63B: possession-based verification (a registered device or hardware security key) and inherence-based verification (biometric data such as fingerprints or facial recognition).

Additional contextual information, like location data, IP reputation, and device trust levels, can enhance these primary factors to provide stronger authentication assurance. It works well when integrated with broader identity and access management strategies that address comprehensive user verification needs.

How Does Passwordless Authentication Work?

Passwordless authentication replaces passwords with more secure alternatives that verify identity through possession, biometric factors, or cryptographic keys. This process eliminates the traditional username-password combination while maintaining robust security through alternative verification methods.

The underlying technology is built on FIDO2/WebAuthn standards, which enable devices to create cryptographic key pairs where the private key remains protected in secure storage and generates signed responses to authentication challenges. Examples of this technology include YubiKey 5 hardware keys, Windows Hello biometric authentication, and mobile passkey implementations.

Here’s how a typical passwordless authentication flow works:

  1. The user initiates a login by entering their username, email, or other identifier on a website or application.
  2. The server sends a challenge to the user’s registered device, requesting proof of identity without a password.
  3. The user’s device prompts them to verify their identity using a passwordless method, such as fingerprint scan, face recognition, PIN, or a hardware security key.
  4. Local authentication (like biometric matching or PIN entry) occurs on the user’s device. The biometric data or PIN is only verified locally and never transmitted to the server.
  5. Once verified, the user’s device uses a private cryptographic key (stored securely on the device) to sign the server’s challenge, creating a unique response that proves device ownership.
  6. The server validates the signed response using the user’s corresponding public key (stored during registration) to verify the cryptographic signature, confirming the user’s identity.
  7. If the verification succeeds, the user can access their account or application.

This approach creates a more secure authentication flow because attackers can’t replay the authentication without access to the user’s physical device, biometric data, or PIN. Cryptographic keys ensure that each authentication session is unique, preventing credential theft and replay attacks that commonly compromise password-based systems.

Passwordless Authentication Methods

Passwordless authentication methods rely on different information or credentials to verify a user’s identity. We’ll explore these methods in detail below.

1. Knowledge Factors, or Something You Know

In passwordless authentication using knowledge factors, passwords are often replaced with alternative methods that are more secure and easier to use. While these methods involve “something you know,” they differ from traditional passwords because the knowledge required changes with each authentication attempt, making them more secure than static passwords.

  • One-Time Codes

These are temporary codes sent to users via email or SMS that expire after a short period, typically within minutes of being generated.

  • Magic Links

Users receive a unique URL via email that, when clicked, automatically authenticates them without requiring password entry. The link contains embedded authentication tokens that verify the user’s identity.

  • Time-Based One-Time Passwords (TOTP)

Generated by authenticator apps like Google Authenticator or Microsoft Authenticator, these codes change every 30-60 seconds based on a shared secret between the app and the server.

Knowledge-based passwordless methods fill the gap for device users without fingerprint readers, cameras, or hardware security keys. These methods, relying on SMS and emails, are convenient for most users since they work on any device or platform.

2. Possession Factors, or Something You Have

In this case, passwordless authentication is carried out through physical objects only a specific user has. These methods rely on devices or tokens that users carry with them to prove their identity, such as:

  • Hardware Security Keys

Physical FIDO2-compliant devices that connect via USB, NFC, or Bluetooth to provide cryptographic authentication. Examples include YubiKey and Feitian security keys.

  • Smart Cards

Cards with embedded chips that store cryptographic keys and require card readers for authentication, commonly used in enterprise environments.

  • Smartphone Push Notifications

Users receive authentication requests on their registered mobile devices, which they can approve or deny with a single tap after local biometric verification.

  • Digital Certificates

Cryptographic credentials are stored on public-key cryptography devices to verify identity without transmitting passwords.

  • Badge Tap and Go

Proximity cards or smart badges with RFID or NFC technology that enable authentication through simple tapping gestures.

According to the FIDO Alliance, possession-based authentication offers a more secure approach by requiring cryptographic proof of device ownership, effectively blocking man-in-the-middle (MITM) attacks. 

FIDO2 technology, for example, ensures that login credentials remain device-specific and locally stored. This prevents phishing attempts and credential theft since no sensitive data is transmitted to servers.

This approach means attackers cannot authenticate even if they intercept communication, as they lack the required physical device. Even if authentication credentials are intercepted, attackers cannot complete the authentication process without the physical possession factor.

3. Inherent Factors, or Something You Are

Passwordless authentication via inherence factors implies submitting physical or behavioral characteristics unique to the user, such as fingerprint, facial recognition, or voice recognition. Inherent factors are becoming increasingly popular because they are highly secure and convenient for users.

  • Biometric Scanning

Includes fingerprint recognition, facial recognition, iris scanning, retina scanning, and voice recognition that verify unique physical characteristics.

  • Behavioral Biometrics

Advanced systems that analyze typing patterns, touchscreen pressure, mouse movement, and device interaction patterns to create unique behavioral profiles.

  • Platform Authenticators

Built-in authentication methods are integrated into device hardware, such as Windows Hello, Touch ID on Mac, or Face ID on mobile devices.

  • Passkeys

FIDO2-based credentials that combine device-specific cryptographic keys with biometric verification, automatically syncing across a user’s ecosystem of devices. 

Gartner’s 2025 Market Guide for User Authentication projects that passkeys will dominate the authentication landscape, with over 90% of token-based MFA logins expected to use FIDO-based passkeys by 2027.

Modern biometric systems can analyze multiple characteristics simultaneously, creating a comprehensive behavioral profile that’s extremely difficult to replicate. Multi-factor biometrics, such as Apple Face ID and Windows Hello, raise the bar for threat actors, as they would need to mimic the entire interaction in real time.

Passwordless Authentication Pros and Cons

Once implemented, passwordless authentication can improve overall security and user experience. However, important factors to consider before implementation include costs and device dependency.

We’ll examine both sides in the table below to help you make an informed decision.

Pros Cons
Increased Security

Passwordless authentication solutions can provide a higher level of security than traditional passwords because they eliminate the need for users to create and remember complex passwords, which are often the weakest link in the cybersecurity chain.

 Not 100% Reliable

Passwordless authentication does not eliminate security risks completely; it’s still vulnerable to SIM swapping attacks or certain types of malware. A more significant threat occurs if a user loses possession of authentication factors. Moreover, threat actors can obtain users’ biometrics, such as voice samples, which makes this method unreliable.
Improved User Experience

Passwordless logins can provide a better user experience than traditional passwords because they eliminate the need for users to remember and manage complex passwords.

 Expensive Implementation

Implementing passwordless authentication beyond basic multi-factor authentication methods like OTPs may be costly because it requires enterprise-grade FIDO2 security keys or biometric hardware, updated identity and access management (IAM) licensing, plus integration and user training expenses.
Long-Term Cost Reductions

Passwordless authentication helps reduce overall security expenses by mitigating common cyber attack risks. This method eliminates the need for password administration and frees up the IT team’s resources.

 Complicated Troubleshooting

Any problems with logging into a system require specific knowledge and a level of proficiency when it comes to passwordless authentication. If a user loses their token or hardware device, replacing the item and taking security countermeasures entails additional costs.

 

Challenges in Adopting Passwordless Authentication at Scale

The challenges in adopting passwordless authentication at scale involve complex technical, organizational, and financial considerations that organizations must address. Understanding and planning for these challenges can help organizations develop effective onboarding strategies for a smoother transition to passwordless authentication methods.

1. Legacy System Integration

Legacy system integration often lacks the necessary APIs or infrastructure to support modern authentication methods, requiring costly development work.

2. User Adoption and Change Management

User adoption challenges may emerge when employees resist new authentication methods, particularly in organizations with diverse user populations. Training programs must address varying comfort levels with technology while ensuring consistent adoption across departments.

3. Device Compatibility and Hardware Requirements

Device compatibility issues arise when passwordless solutions must work across multiple operating systems and hardware configurations. Users may lack compatible hardware like biometric sensors on their devices, requiring alternative authentication methods for these exceptions.

4. Backup and Recovery Planning

Sometimes, users lose access to authentication devices like smartphones or hardware tokens. To address this, you’ll need secure recovery mechanisms that don’t introduce new security vulnerabilities or create excessive administrative overhead.

This challenge often overlaps with email security concerns, as recovery communications may become targets for phishing attacks attempting to exploit the recovery process.

5. Performance and Infrastructure Demands

Performance issues may emerge when biometric processing and cryptographic operations strain the network infrastructure during large-scale deployments and peak usage periods.

Best Practices for Implementing Passwordless Authentication

The best practices for implementing passwordless authentication center on careful planning, gradual deployment, and continuous monitoring to ensure successful adoption.

Here are the key practices that you should follow:

1. Assess Your Authentication Needs

Validate the need to implement this method in your case. Compare your risks against the opportunities that passwordless authentication offers.

2. Choose the Proper Authentication Method

Many types of passwordless authentication are available, such as those mentioned above. Choose the method that best suits your organization’s needs and requirements.

3. Educate Users

Educate users on passwordless authentication and its benefits. This can help increase adoption and reduce confusion.

4. Test and Validate

Test and validate the selected passwordless authentication system before deploying it to ensure it is secure and works as intended.

5. Monitor and Review

Monitor and review your passwordless authentication system regularly to ensure it is still secure and meets your organization’s needs.

6. Prepare for Troubleshooting in Advance

Have contingency plans ready in case of system failures or other issues that may impact the availability or security of your passwordless authentication system.

7. Implement Gradual Rollout

Start with pilot groups or less critical systems before expanding to your organization. This approach allows you to identify and resolve issues while minimizing business disruption.

8. Maintain Backup authentication methods

Always have alternative authentication methods available if primary passwordless systems fail or users lose access to their authentication devices.

Implement Passwordless Authentication with Group-IB’s Fraud Protection

Passwords are still attackers’ easiest target, yet ripping them out can feel risky if you’re unsure what replaces them. Group-IB bridges that gap by pairing device-centric, risk-based authentication with its established Fraud Protection and Business Email Protection platforms.

Now, the result is a layered approach. Your users can log in through passkeys or push approvals, while every session is scored in real time for signs of bots, credential-stuffing, or business email compromise.

If you’re exploring passwordless security and want concrete, measurable results rather than marketing hype, consider the following steps:

  1. Talk with a Group-IB specialist. Map your high-risk login flows and define clear success metrics.
  2. Get Business Email Protection. Continuous monitoring blocks BEC and reply-chain phishing, two of the most common routes attackers use to harvest credentials.
  3. Expand in phases. Add additional channels and integrate Business Email Protection to close phishing gaps as you go.
  4. Threat Intelligence and Attribution. Get up-to-the-minute data on active phishing kits, botnets, and mule networks, feeding risk scores so your passwordless rollout stays ahead of new tactics.

If you’d like a demo or a proof-of-concept, Group-IB’s team can show precisely how the risk engine plugs into your web or mobile flow and what lift it removes from the SOC.