Biometrics & MFA: What Really Brings Security

What It's Really About

Anyone still believing that a password plus "something with push" is sufficient hasn't understood the reality of attacks. Attackers don't just steal passwords anymore; they hijack sessions, exploit weak devices, bypass SMS codes, and use so-called Adversary-in-the-Middle chains to hijack logins in real-time. MFA is therefore not a "nice-to-have," but the minimum to increase the cost per attack. But: MFA is not the same as MFA. Between phishing-prone methods (e.g., one-time codes, freely confirmable pushes) and phishing-secure methods (e.g., Passkeys/FIDO2 with device binding) lies a security chasm. Cutting corners in the wrong place buys a false sense of security – and costs double in the event of an incident: in time and downtime costs.

Biometrics Without Romance

Biometrics works because it links the "possession" factor to a specific, registered device while simultaneously utilizing the "inherence" factor (e.g., finger, face) to make local unlocking secure and fast. But biometrics is no magic spell. The key point is where the verification happens and how the cryptographic proof looks. If unlocking occurs locally in the device's secure element, and the private key never leaves its boundaries, a qualitatively different level of protection is achieved compared to solutions that evaluate biometric data server-side or send simple app approvals. When implemented correctly, biometrics brings speed for users and integrity for the organization: fewer password resets, less social engineering exposure, less friction in daily operations. When done wrong, it creates new risks: questionable enrollments, insecure devices, lack of policies for loss cases, and no proper fallback if the sensors fail.

Why Phishing-Secure MFA Makes the Difference

Phishable methods can be deceived because the human in the loop cannot verify the authenticity of the counterpart. A fake login portal, a forwarded one-time code – and the attacker is in the session. Phishing-secure MFA cryptographically binds the login to the legitimate website or app. This means that even if a user willingly "confirms," the confirmation cannot be redirected to another domain. Zero Trust becomes tangible here: don't trust, verify; don't trust globally, but bind to context – identity, device, application. In practice, this shows up in attacks with very little negotiation room: without the correct private key and the proper counterpart, the door stays locked. This is the difference between "we had MFA" and "the attack failed technically."

The Uncomfortable Questions About Your Own Implementation

Anyone serious about security doesn't just roll out buzzwords, but answers a few uncomfortable questions: Where do we still accept SMS codes or email links – and why? Where do we allow push confirmations without contextual binding? Which privileged roles (Admin, Finance, HR, Developers) have already switched to phishing-secure MFA, and which have not? How do we handle "Legacy" – services that can only do basic authentication? And what happens if devices are lost: Is the recovery process documented, verifiable, and fast, or do we improvise? These answers determine the actual cyber risk, not the number of licenses.

Practical Guide Without Hype

The path is clear and free of religion. First: start where a breach would hurt the most – privileged roles and externally exposed access points. Second: Replace weak factors with strong ones. MFA with Passkeys or FIDO2 security keys on corporate devices drastically reduces phishing success because the login and target page are cryptographically linked. Third: Enforce session hygiene. A strong login is useless if a stolen token lives for weeks. Therefore, set short session durations, re-challenges at risk (unusual location, new device, sensitive process), and clear revocation mechanisms. Fourth: Regulate fallbacks. No procedure is perfect. The secure emergency path must be rare, short, and strict – time-limited, clearly approved, and revoked immediately afterward. Fifth: Don't forget the machines. Service accounts, CI/CD tokens, and IoT devices also need strong, short-lived login credentials and mTLS-based connections, or the backdoor remains open.

What Can Be Measured Can Be Improved

Metrics are not an end in themselves, but without numbers, everything is just a feeling. Useful metrics include the coverage of phishing-secure MFA for critical roles, the average session life in sensitive applications, the time from device loss to complete revocation of all access, the rate of blocked login attempts through domain binding, and the percentage of privileged actions that require additional step-up verification. What matters is consistency: a deviation should not trigger "we are observing," but a predefined action – block, rotate, refine.

Conclusion: Speed Plus Integrity

The best IT security is the one that's used – daily, without friction, without excuses. Biometrics and phishing-secure MFA deliver just that when implemented correctly: fast logins, strong binding to legitimate targets, clear revocation paths. Those who consistently switch today reduce the attack surface, shorten response time, and lower hidden costs that would otherwise seep into helpdesk, forensics, and downtime. Everything else is just cosmetics – and cosmetics have never stopped an attack.