Phishing-Resistant MFA: What It Is and Why You Need It

2 September 2025

Phishing-Resistant MFA: What It Is and Why You Need It

2 September 2025

From the World Economic Forum’s Global Cybersecurity Outlook, 2025, 42% of organizations experienced phishing, vishing, deepfakes, or other social engineering attacks in 2024. And according to Liminal Research, in 2024 phishing was the most significant account takeover (ATO) threat vector, accounting for 26.7% of all account takeovers and standing as the most common method attackers use to access user accounts.

Cybercriminals often use phishing to steal passwords, gain unauthorized access to sensitive data, and cause financial damage. But as attackers grow more sophisticated, it's no longer enough to rely on basic multi-factor authentication (MFA) methods like SMS one-time passwords (OTPs).

In this blog, we’ll explain what phishing-resistant MFA is, why it’s essential for securing accounts and preventing breaches, and how businesses can implement it to protect both users and sensitive data.

What is MFA?

Multi-factor authentication (MFA) is a security mechanism that requires users to verify their identity using more than one method. This typically involves:

Something you know (a password or PIN).
Something you have (a mobile device or security token).
Something you are (biometric data like a fingerprint or face scan).

Traditional MFA often uses something you know (passwords) along with something you have (SMS OTPs). While this adds an extra layer of protection, it still leaves vulnerabilities that attackers can exploit. For example, phishing and SIM swap attacks are commonly used to steal credentials or intercept OTPs.

What Is Phishing-Resistant MFA?

Phishing-resistant MFA goes beyond traditional methods by utilizing stronger authentication factors that are less likely to be stolen or intercepted through phishing attacks. Unlike SMS-based or email-based OTPs, phishing-resistant MFA employs methods like hardware tokens, biometrics, or push notifications, which are much harder for attackers to exploit.

Some examples of phishing-resistant MFA include:

Biometric authentication (e.g., face or fingerprint recognition).
Push notification approvals (e.g., approve login via an app on a trusted device).
Passkeys (cryptographic credentials stored on a device).
Security keys (hardware tokens like YubiKey).
Device binding (ensuring the authentication request comes from a previously registered device).

These methods are not just more secure, they are designed to eliminate the common weaknesses of traditional authentication methods, making it nearly impossible for attackers to bypass them.

Does Phishing-Resistant MFA Always Work?

"Phishing-resistant" is a hot buzzword in the authentication space. For a technology to be truly resistant to phishing attacks, it needs to prevent phishing completely. Currently, there isn’t a technology that can do this; cybersecurity is a cat-and-mouse game - there likely never will be.

However, many technologies, like Keyless, significantly reduce the likelihood of phishing in certain contexts. So although no companies are 100% phishing-resistant – and any company that professes to be so would be lying – many still use the terminology as it is understood that nobody is there yet. So, phishing-resistant MFA means "using the strongest forms of MFA to prevent phishing to a high degree."

Why Is Phishing-Resistant MFA Important?

Phishing attacks are becoming more sophisticated every year, with attackers using a variety of techniques to trick users into revealing their credentials. In fact, Verizon’s 2024 Data Breach Investigations Report (DBIR) found that over 30% of all breaches involved phishing.

1. Phishing Can Bypass SMS OTPs and Passwords

SMS OTPs and passwords can be easily compromised. For example, attackers can:

Trick users into entering credentials on fake websites or through fake emails.
Intercept OTPs via SIM swap attacks, where a fraudster gains control of the victim's phone number.

2. Better Protection for High-Risk Transactions

In industries like banking, financial services, and healthcare, phishing-resistant MFA is crucial for protecting high-risk transactions and sensitive data. For example, a fraudster can’t just steal a user’s password and bypass biometric authentication or security keys, preventing account takeovers and fraud.

3. Meeting Compliance Standards

Many regulations, such as PSD2 in Europe and NIST SP 800-63 in the U.S., require stronger, phishing-resistant MFA for securing digital transactions and data access. Implementing these methods ensures that businesses meet these compliance standards while also protecting users from fraud.

Types of Phishing-Resistant MFA

To understand the effectiveness of phishing-resistant MFA, let’s dive into some common methods:

1. Biometric Authentication + Device Binding

Biometric authentication (like facial recognition or fingerprint scanning) is one of the most effective ways to authenticate users. When combined with device binding, which ensures that the device used for authentication is the same one registered during onboarding, it becomes virtually impossible for an attacker to impersonate the user.

2. Push Notification Approval

Push notifications sent through a trusted mobile app combine device possession and user intent. When users receive a notification asking them to approve or deny a login attempt, the action is both fast and secure. If the user didn’t initiate the login, they simply deny the request. Typically, these push notifications are used via authenticator apps but can also be used directly in consumer apps like banking.

3. Security Keys

Hardware security keys (e.g., YubiKey) are small physical devices that generate unique authentication codes. These keys use public-key cryptography, which makes them resistant to phishing, man-in-the-middle, and even keylogging attacks. However, they are easily lost and mostly used in workforce environments.

4. Passkeys

Passkeys are cryptographic credentials stored on a device that can be used to log into accounts securely. They are not transmitted in plaintext and cannot be intercepted by attackers. When combined with biometric authentication, passkeys can form a phishing-resistant MFA solution that’s fast, secure, and seamless.

5. One-Time Passwords via Authenticator Apps

Unlike SMS-based OTPs, authenticator apps (e.g., Google Authenticator, Authy) generate time-sensitive codes that are never sent via email or text. These codes are generated locally on the device and are more secure, as they cannot be intercepted during transmission.

Why Choose Keyless for Phishing-Resistant MFA?

At Keyless, we specialize in biometric-based phishing-resistant MFA that provides the highest level of security while maintaining a smooth user experience. Our solution uses:

Facial recognition with passive liveness detection to ensure that the user is physically present and not using a spoofed image.
Device binding to ensure that login attempts are made from the registered device.
Zero-Knowledge Biometrics™ technology, which ensures that biometric data is never stored or exposed, protecting user privacy and meeting regulatory compliance.

With Keyless, you get a phishing-resistant MFA solution that’s designed to stop fraud at the point of authentication while enhancing the user experience.

Final Thoughts: Protecting Against the Growing Threat of Phishing

As phishing attacks become more sophisticated, relying on traditional authentication methods like SMS OTPs or passwords is no longer enough. Phishing-resistant MFA offers a stronger, more secure way to verify users and protect against fraud. It’s no longer a luxury – it’s a necessity, especially in high-risk industries.

Keyless provides a comprehensive, privacy-first MFA solution that’s phishing-resistant, fast, and seamless. By using biometric authentication and device binding, Keyless protects your users and your business from the growing threat of phishing attacks.

Ready to protect your accounts from phishing?

Request your 3-minute on-demand personalised demo today.

Phishing-Resistant MFA: What It Is and Why You Need It

2 September 2025

Phishing-Resistant MFA: What It Is and Why You Need It

2 September 2025

What is MFA?

What Is Phishing-Resistant MFA?

Does Phishing-Resistant MFA Always Work?

Why Is Phishing-Resistant MFA Important?

1. Phishing Can Bypass SMS OTPs and Passwords

2. Better Protection for High-Risk Transactions

3. Meeting Compliance Standards

Types of Phishing-Resistant MFA

1. Biometric Authentication + Device Binding

2. Push Notification Approval

3. Security Keys

4. Passkeys

5. One-Time Passwords via Authenticator Apps

Why Choose Keyless for Phishing-Resistant MFA?

Final Thoughts: Protecting Against the Growing Threat of Phishing

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