1. Introduction: Why Passwords Are Becoming a Security Problem

A single compromised password can give an attacker access to email, corporate applications, cloud platforms, and sensitive business information. The risk becomes even greater when users reuse passwords across multiple services.

Attackers exploit these weaknesses through phishing campaigns, credential stuffing, password spraying, infostealer malware, and social engineering. Even organisations that enforce complex password policies can experience account compromises when users unknowingly disclose their credentials.

Multi-factor authentication (MFA) provides an additional layer of protection, but not all MFA methods offer the same level of security. Attackers can sometimes steal session cookies, trick users into approving fraudulent requests, or relay authentication codes through phishing pages.

Passkeys offer a different approach. Instead of relying on a shared secret that users type into a website, passkeys use cryptographic key pairs to verify authentication. This design helps protect users against several common credential theft techniques.

The shift towards passkeys is not simply a change in how people sign in. It represents a move towards authentication systems designed to make phishing and credential reuse much harder.

2. How Traditional Password Authentication Works

Passwords authenticate users through a secret that is typically known to the user and verified by the service.

When a user creates an account, the service normally stores a password verifier, commonly produced using a salted password-hashing function. During login, the submitted password is processed and compared with the stored verifier.

A simplified authentication flow looks like this:

1. The user enters a username and password.

2. The application securely transmits the login credentials over an encrypted connection.

3. The authentication service verifies the password against its stored password verifier.

4. If the credentials are valid, the service establishes an authenticated session.

Although this process is widely used, its security depends on users protecting their passwords and services implementing authentication securely.

Common attacks against passwords

Phishing: Attackers create fake login pages that imitate trusted websites and capture credentials entered by victims.

Credential stuffing: Attackers use usernames and passwords leaked from one service to attempt access to other services.

Password spraying: Attackers try a small number of commonly used passwords against many accounts to avoid triggering some account-specific security controls.

Brute-force attacks: Attackers repeatedly guess passwords until they discover a valid credential, subject to the strength of the password and the effectiveness of protective controls.

Infostealer malware: Malware can steal credentials saved in browsers or other accessible locations, depending on the malware's capabilities and the device's security.

Data breaches: If an organisation's password database is exposed, attackers may attempt to crack stolen password hashes, especially where weak passwords or inadequate password-storage practices are involved.

Strong, unique passwords and a reputable password manager reduce several of these risks. However, they do not eliminate the fundamental problem of users entering reusable secrets into potentially malicious websites.

3. What Are Passkeys?

Passkeys are passwordless credentials based on public-key cryptography. They are designed to let users authenticate without typing a traditional password.

A passkey consists of a cryptographic key pair:

• Private key: Used to produce a cryptographic response during authentication. It is protected by the authenticator and is not ordinarily sent to the website.

• Public key: Registered with the service and used to verify the authentication response.

Depending on the platform and configuration, a passkey may be stored and synchronised through a credential provider or protected by a device-bound authenticator. Users may unlock the authentication process using a fingerprint, facial recognition, device PIN, or another supported local verification method.

Biometrics do not normally replace the cryptographic key. They help the device authorise the use of the credential.

How passkey authentication works

1. The user registers a passkey with a website or application.

2. The service stores the corresponding public key and associates it with the account.

3. During login, the service sends an authentication challenge.

4. The authenticator uses the private key to sign the challenge after any required user verification.

5. The service verifies the signature using the registered public key.

6. If verification succeeds, the service establishes an authenticated session.

The private key is not sent to the website as part of this process. The service verifies proof of possession of the key rather than asking the user to reveal a reusable secret.

Passkeys commonly use the FIDO2 and WebAuthn standards, with platform authenticators and external security keys supporting different authentication experiences.

4. Passkeys vs. Passwords: Key Differences

Security featurePasswordsPasskeysAuthentication methodShared secret entered by the userPublic-key cryptographyPhishing resistanceVulnerable to fake login pagesDesigned to resist phishing through relying-party bindingCredential reuseUsers may reuse passwordsCryptographic credentials are associated with the registered serviceCredential database exposureStolen password hashes may be crackedPublic keys alone do not reveal the private keyUser experienceRequires entering or retrieving a passwordOften uses a device prompt, biometric, or PINBrute-force exposureDepends on password strength and controlsNo traditional password to guess during passkey authenticationAccount recoveryUsually password reset or recovery flowDepends on credential synchronisation, backup, and account recovery designDeploymentSupported by almost all online servicesRequires compatible services, authenticators, and recovery processes

Passkeys offer important security advantages, but they do not automatically make every part of an authentication system secure. Account recovery, session management, device security, and administrative controls remain critical.

5. Why Passkeys Are More Resistant to Phishing

Phishing succeeds when an attacker convinces a victim to disclose information or approve an authentication request that benefits the attacker.

Traditional passwords can be entered into a fake login page. The attacker may then use the captured password to access the legitimate service.

Passkeys work differently. WebAuthn authentication is tied to the legitimate relying party, including the website's origin. A credential registered for one domain cannot normally be used to authenticate to an unrelated phishing domain.

Consider this scenario:

An employee receives an email claiming that their corporate account will be suspended unless they sign in immediately. The link opens a convincing imitation of the company's login page.

With a password-based login, the employee may enter their credentials, allowing the attacker to capture them.

With a correctly implemented passkey flow, the fake website cannot simply request a valid authentication response for the legitimate corporate domain. The origin-binding protections help prevent the attacker from reusing the authentication interaction on the real service.

This is a major security advantage over passwords and many forms of one-time-code MFA.

However, passkeys do not eliminate every phishing-related risk. Attackers may still target recovery procedures, steal active sessions, compromise devices, exploit vulnerable applications, or trick users into authorising access through other mechanisms.

6. Can Passkeys Be Hacked?

Passkeys substantially reduce certain credential-based attack paths, but they are not invulnerable.

Device compromise

If an attacker gains significant control over a user's device, they may attempt to abuse an already authenticated session or interfere with the authentication process. The exact risk depends on the operating system, authenticator, malware capabilities, and security controls.

Account recovery attacks

An attacker may target email accounts, recovery codes, help desks, or identity-verification processes to regain access without needing to defeat the passkey itself.

Compromised synchronisation accounts

Some passkeys can be synchronised across devices through a credential provider. If an attacker compromises the account that protects this synchronisation process, the risk depends on the provider's security architecture, recovery controls, and additional protections.

Session cookie theft

After successful authentication, many applications issue session cookies or other session tokens. Malware or an attacker with access to a compromised browser may steal these tokens and attempt to reuse them.

Passkeys primarily protect the authentication step; they do not automatically protect every session created afterwards.

Social engineering and malicious approvals

Attackers may still deceive users into granting access to applications, approving account changes, or disclosing sensitive information. Strong authentication must be combined with clear consent flows and effective monitoring.

The important distinction is that passkeys change the attacker's problem. Rather than simply stealing a password, the attacker may need to compromise the endpoint, session, recovery mechanism, or another part of the identity system.

7. Passkeys and Multi-Factor Authentication

Passkeys are often described as passwordless authentication, but their security properties are more important than the label.

A passkey protected by a local biometric or PIN can combine possession of an authenticator with local user verification. This can provide strong authentication without requiring users to enter separate credentials.

Nevertheless, organisations should distinguish between:

• SMS one-time codes: Vulnerable to phishing, SIM-swapping attacks, and interception in some circumstances.

• Authenticator-app codes: Better than relying on passwords alone, but can still be phished or relayed in real time.

• Push-based MFA: Can be abused through repeated approval requests or social engineering if safeguards are weak.

• FIDO2 security keys and passkeys: Designed to provide phishing-resistant authentication when correctly implemented.

A passkey is not simply another code sent to a user. Its cryptographic design binds authentication to the legitimate service, which is why it offers a stronger defence against credential phishing.

Organisations should still assess their complete authentication design, including local verification requirements, privileged-account policies, recovery options, and session protections.

8. How SOC Teams Can Detect Attacks Involving Passkeys

Moving to passkeys changes what security operations teams should investigate. Traditional alerts focused on repeated incorrect passwords may become less relevant for accounts that use passwordless authentication.

SOC analysts should pay attention to suspicious activity surrounding authentication, account recovery, device trust, and post-login sessions.

Important investigation signals

Unusual successful logins: Investigate successful authentication from unfamiliar locations, devices, or network environments, particularly when followed by sensitive actions.

New device or authenticator registration: Review unexpected additions, removals, or changes to authentication methods, especially for privileged accounts.

Account recovery activity: Examine unusual password resets, recovery attempts, help-desk verification events, or changes to recovery information.

Session anomalies: Investigate suspicious session creation, token reuse, unusual refresh activity, or access from unexpected devices where the relevant telemetry is available.

Privilege escalation: Correlate suspicious authentication with role changes, administrator consent grants, new API credentials, or modifications to identity policies.

Repeated authentication failures: Investigate patterns that may indicate account discovery, user confusion caused by an attack, or attempts to exploit a fallback authentication method.

Practical investigation workflow

1. Validate the authentication event. Identify the user, application, timestamp, authentication method, result, device details, and available client or network information.

2. Review identity changes. Check for new passkey registrations, authenticator removals, recovery changes, and changes to MFA or conditional-access policies.

3. Correlate identity and endpoint telemetry. Look for suspicious browser activity, malware alerts, new processes, or unusual access from the affected device.

4. Examine post-authentication activity. Review application access, file downloads, mailbox rules, cloud resource changes, and privilege modifications.

5. Assess the scope. Search for related activity across the same account, device, IP address, application, and relevant time window.

6. Contain and recover. Depending on the evidence, revoke sessions, disable suspicious credentials, isolate a compromised endpoint, and restore secure account access.

7. Document the findings. Record the timeline, evidence, affected assets, containment actions, and recommended improvements.

Example SIEM investigation

Suppose a privileged employee authenticates using a passkey from a new device. Minutes later, the account creates a new administrator and downloads a large volume of sensitive data.

The successful passkey authentication does not, by itself, establish that the activity is malicious. The SOC should correlate the sign-in with device history, user behaviour, privilege changes, data-access logs, and any related endpoint detections.

The investigation should determine whether the user performed the actions legitimately, whether their device or session was compromised, or whether another identity-management weakness was exploited.

Key lesson: Strong authentication reduces the likelihood of credential theft, but identity monitoring must continue after a successful login.

9. Implementing Passkeys in an Organisation

A successful deployment requires more than enabling a passwordless sign-in option.

Start with high-risk accounts

Prioritise administrators, cloud engineers, security personnel, remote-access users, and other accounts with access to sensitive systems. Require phishing-resistant authentication where supported by the organisation's identity platform and risk model.

Establish secure recovery procedures

Define how users regain access when a device is lost or replaced. Recovery should not become an easier route for attackers than normal authentication.

Use strong identity verification, appropriate approval workflows, auditable changes, and alerts for high-risk recovery activity.

Protect endpoints and sessions

Maintain endpoint detection and response coverage, operating-system updates, browser security, device management, and appropriate session controls. Passkeys should complement these measures rather than replace them.

Monitor credential lifecycle events

Log and review passkey registration, removal, recovery, authentication failures, policy changes, and unusual sign-in behaviour wherever the identity platform exposes these events.

Retain fallback authentication carefully

Some users or applications may not support passkeys. Review fallback methods to ensure that attackers cannot bypass a strong passkey requirement simply by selecting a weaker option.

Educate users and support teams

Explain how legitimate authentication prompts work, how to recognise unexpected recovery requests, and how to report suspicious account activity. Help-desk staff should understand the risks of social engineering and unauthorised credential resets.

10. Should Organisations Completely Replace Passwords?

Passkeys are a strong candidate for the future of everyday authentication, but organisations should not assume that all passwords can be removed immediately.

Legacy applications, service accounts, third-party integrations, and systems with limited authentication support may still depend on passwords. Some environments also have regulatory, operational, or accessibility requirements that affect deployment.

A practical transition can include:

• Introducing passkeys for supported workforce applications.

• Prioritising privileged and high-risk users.

• Requiring phishing-resistant authentication for sensitive operations.

• Restricting weak fallback methods.

• Improving recovery and identity-verification processes.

• Monitoring authentication and session activity centrally.

• Measuring adoption, account compromise rates, recovery incidents, and support requirements.

Passwords may remain necessary during the transition, but organisations can reduce their exposure by using unique passwords, password managers, rate limiting, breached-password screening, and strong MFA wherever passkeys are unavailable.

The goal is not simply to remove passwords. It is to reduce the opportunities attackers have to impersonate legitimate users.

Conclusion: A Stronger Future for Digital Identity

Passwords helped make online authentication accessible, but their dependence on reusable secrets has created persistent security challenges. Phishing, credential stuffing, infostealer malware, and password reuse continue to provide attackers with practical ways to compromise accounts.

Passkeys address an important part of this problem through public-key cryptography and relying-party binding. They make traditional password theft and reuse less useful and provide strong resistance to many phishing attacks.

However, authentication is only one layer of defence. Compromised devices, stolen sessions, insecure recovery processes, excessive privileges, and social engineering can still put accounts at risk.

For security teams, the future of authentication will involve more than replacing passwords with passkeys. It will require a broader identity-security strategy that combines phishing-resistant authentication, endpoint protection, session security, continuous monitoring, and secure account recovery.

The future is not just passwordless authentication. It is authentication that makes impersonation significantly harder while giving defenders better visibility into what happens after a user signs in.