From Passwords to Passkeys: A Phased Migration Plan for Existing Users

Passwords once made sense. 

In the early days of digital services, a shared secret was an acceptable way to prove identity. Today, users access services across multiple devices, and attackers exploit phishing, credential reuse, and stolen password databases at scale. 

Passwords have become one of the most fragile and costly elements of security, causing account takeovers, support tickets, and user frustration.

Passkeys offer a modern solution. But what is a passkey, and how do passkeys work? A passkey is a passwordless authentication credential that uses cryptographic keys instead of shared secrets.

The private key stays securely on the user’s device, while the public key is registered with the service. When signing in, the device proves possession of the private key without transmitting it, making login faster, simpler, and more secure.

For organisations with existing users, the challenge is not whether to adopt passkeys, but how. Removing passwords too quickly can confuse users and disrupt workflows. 

A phased migration gradually introduces passkeys alongside passwords, ensuring a smooth transition. This guide explains what a passkey is, explores how do passkeys work, and provides a step-by-step approach to migrate users safely and confidently.

The Growing Problem With Password-Based Authentication

Passwords were never designed for the scale and complexity of today’s digital environments. Users now manage dozens, sometimes hundreds, of online accounts. Expecting them to create strong, unique passwords for each service is unrealistic.

As a result, users adopt unsafe behaviours. Passwords are reused across services, stored insecurely, or simplified to make them easier to remember. Even well-intentioned users fall victim to phishing emails and fake login pages that capture credentials in seconds.

From an organisational standpoint, passwords introduce constant friction. Help desks are flooded with reset requests. 

Account lockouts interrupt productivity. Security teams must monitor for leaked credentials and suspicious login activity. Despite significant investment, passwords remain a persistent vulnerability.

These challenges have pushed organisations to explore passwordless authentication models that remove shared secrets entirely.

Understanding Passkeys and Passwordless Authentication

To plan a successful migration, organisations must first establish a clear understanding of what passkeys are and how they work.

What is a passkey?

A passkey is a passwordless authentication credential that uses public key cryptography instead of shared secrets. When a user creates a passkey, a cryptographic key pair is generated. The private key is stored securely on the user’s device, while the public key is registered with the service.

The private key never leaves the device. Authentication is performed by proving possession of that key, typically unlocked using biometric authentication or a device PIN. This eliminates the need for users to remember or manage passwords.

How does a passkey work?

When a user attempts to sign in, the service sends a cryptographic challenge to the user’s device. The device signs the challenge using the private key and returns the signed response. The service verifies the response using the public key on file.

This process explains how does a passkey work: authentication relies on cryptographic proof rather than shared knowledge. Because the private key is never transmitted or stored on the server, it cannot be stolen in a data breach.

How do passkeys work in everyday use?

In everyday use, passkeys feel simple and intuitive. Users authenticate with a fingerprint, face scan, or device PIN. The cryptography happens behind the scenes, creating a seamless experience that is both faster and more secure than typing a password.

Open Standards and the Importance of FIDO2

One of the strongest advantages of passkeys is that they are built on open standards rather than proprietary technology.

What is FIDO2?

What is FIDO2 refers to a set of authentication standards developed by the FIDO Alliance in collaboration with the World Wide Web Consortium. FIDO2 defines how browsers, devices, and servers work together to enable secure, passwordless authentication using public key cryptography.

Because FIDO2 is widely supported across platforms and vendors, organisations can deploy passkeys without being locked into a single ecosystem. This ensures long-term flexibility and interoperability.

Password vs Passkey: Explaining the Difference to Users

Clear communication is critical during any authentication change. Users need to understand why passkeys are safer and how they differ from passwords.

Password vs passkey

A password is a shared secret. The user knows it, and the service stores a version of it. If that secret is exposed, attackers can reuse it anywhere the user has reused the same password.

A passkey is not a shared secret. The service never knows the private key, and authentication cannot be replayed or reused elsewhere. This fundamental distinction makes passkeys resistant to phishing and credential theft.

What is a passkey vs password

Explaining what is a passkey vs password helps users understand that passkeys are not simply “stored passwords.” They are cryptographic credentials tied to the user’s device and protected by local security mechanisms.

Difference between password and passkey

The difference between password and passkey can be summarised simply:

• Passwords rely on memory and secrecy
• Passkeys rely on cryptographic proof
• Passwords can be stolen
• Passkeys cannot be phished or guessed

This clarity builds trust and encourages adoption.

Why a Phased Migration Is the Safest Approach

Despite their advantages, passkeys should not be introduced abruptly for existing users. Organisations must account for legacy systems, diverse devices, and varying levels of technical comfort. A phased migration allows organisations to:

• Preserve backward compatibility
• Introduce change gradually
• Educate users over time
• Reduce support overhead
• Measure adoption and adjust strategy

This approach prioritises user confidence and operational stability.

Phase 1: Preparing Infrastructure and Teams

The first phase focuses on readiness rather than user-facing changes.

Modernising Identity Infrastructure

Organisations must ensure their identity systems support passkey registration, authentication, and recovery. This typically involves upgrading or adopting an IAM platform that supports FIDO2-based authentication.

During this phase, passwords remain the default login method, but passkey capabilities are enabled in the background.

Internal Education and Alignment

Support, IT, and security teams must understand passkeys deeply. They should be able to explain what is a passkey, address common concerns, and troubleshoot issues. Internal alignment ensures consistent messaging once users are introduced to passkeys.

Phase 2: Introducing Passkeys as an Optional Feature

Once infrastructure is ready, passkeys should be offered as an opt-in option for existing users.

User Communication and Education

Clear communication is essential. Users should understand why passkeys are being introduced, how they improve security, and that passwords will continue to work during the transition.

Guides and onboarding flows should explain how to create a passkey in simple, non-technical language, emphasising convenience and safety.

Supporting Multiple Devices

Many users work across phones, tablets, and laptops. Modern passkey implementations allow secure synchronisation across trusted devices, reducing the risk of lockout and improving usability.

Phase 3: Platform-Specific Guidance and Adoption

Providing platform-specific guidance increases confidence and reduces friction.

How to create a passkey on Android

Android devices support passkeys through compatible browsers and system services. When users register a passkey, it is stored securely and protected by biometric authentication or a device PIN.

Clear instructions for how to create a passkey on android help mobile-first users adopt passkeys quickly and confidently.

How to use Apple passkey

Apple has deeply integrated passkeys into its ecosystem. Passkeys are synced securely across Apple devices using iCloud Keychain, allowing users to authenticate seamlessly on iPhone, iPad, and Mac.

Guidance on how to use apple passkey reassures users that their credentials are both secure and recoverable.

Phase 4: Driving Adoption Through User Experience Design

Once passkeys are available, user experience design becomes a key driver of adoption.

Contextual Prompts and Education

After a successful password login, users can be prompted to create a passkey. These prompts should be informative, optional, and clearly explain the benefits.

This is an ideal opportunity to reinforce how do passkeys work and why they are safer than passwords.

Making Passkeys the Preferred Option

Over time, organisations can make passkey login more prominent while still supporting passwords. This gentle nudge encourages behaviour change without forcing it.

Phase 5: Managing Passkeys and Recovery Securely

As adoption increases, organisations must address management and recovery concerns.

Passkey Storage and Management

Users may ask where their passkeys are stored and whether they need a password manager. In many cases, passkeys are stored in platform-native systems or a dedicated passkey password manager that supports secure synchronisation.

Clear guidance helps users understand how their credentials are protected.

Account Recovery Strategies

Because passkeys are device-bound, recovery flows must be thoughtfully designed. Organisations should support:

• Multiple registered devices
• Secure backup authentication options
• Identity verification processes

Strong recovery mechanisms maintain trust without reintroducing weak security practices.

Phase 6: Making Passkeys the Default Authentication Method

Once adoption reaches a critical threshold, organisations can shift passkeys from optional to preferred.

Passwordless Onboarding for New Users

New users can be onboarded with passkeys by default, eliminating password creation entirely. Existing users can continue using passwords temporarily while being encouraged to migrate.

Gradual Password Decommissioning

Over time, password usage can be reduced and eventually deprecated for most users. Communication should continue to reinforce the difference between password and passkey and the security benefits of the change.

Measuring Migration Success

A phased approach allows organisations to track progress and refine their strategy.

Key metrics include:

• Percentage of users with registered passkeys
• Passkey authentication success rates
• Reduction in password reset tickets
• Decrease in phishing-related incidents
• User satisfaction with login experience

These metrics demonstrate both security improvements and operational efficiency.

Business Benefits of Moving From Passwords to Passkeys

The benefits of passkeys extend beyond improved security. Organisations experience reduced support costs, fewer account compromises, and smoother user experiences.

Users spend less time managing credentials and more time engaging with services. Security teams benefit from reduced attack surfaces and fewer incidents related to stolen credentials.

Over time, passkeys enable a future where authentication is strong by default and invisible to the user.

Bottom Line

Passwords are no longer sufficient for modern security and usability requirements. Passkeys provide a secure, scalable, and user-friendly alternative built on open standards such as FIDO2.

By understanding what is a passkey, clearly explaining password vs passkey, and following a phased migration strategy, organisations can transition existing users without disruption.

Modern IAM platforms like Authgear make this transition practical and scalable. With built-in support for passkeys, FIDO2-based authentication, automated identity flows, and seamless integration across platforms, Authgear helps organisations modernise authentication without adding complexity.

Start your free Authgear trial today and begin your journey from passwords to passkeys with a flexible, secure IAM foundation that grows with your users.

FAQs

Why should organisations move from passwords to passkeys?

Passwords are vulnerable to phishing, reuse, and breaches, while passkeys use cryptographic authentication that cannot be stolen or reused, significantly improving security and user experience.

Can passkeys replace passwords for existing users immediately?

A phased migration is recommended so existing users can transition gradually without disruption, while maintaining compatibility with legacy systems and devices.

Are passkeys secure if a user loses their device?

Yes. Passkeys are protected by device-level security such as biometrics or a PIN, and recovery options like additional devices or identity verification can be used to regain access.

Do passkeys work across different devices and platforms?

Yes. Passkeys are based on open standards like FIDO2 and are supported across major platforms, with secure synchronisation between trusted devices.

How do passkeys reduce IT and support overhead?

By eliminating password resets, reducing login failures, and preventing credential-based attacks, passkeys significantly lower support tickets and operational costs.

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