Hardware security keys, like the YubiKey described below, offer strong defense against many cyber threats, including spoofed websites, phishing attacks and on-path (aka “man in the middle“) attacks…
And, while they’re not completely foolproof, a hardware key that requires local biometric authentication can be more effective against potential remote access quantum computing threats than a password or 2FA authentication (SMS or using Google Authenticator) approach alone.
This article describes the three “Tiers” of authentication security and why you should consider moving from “Tier I – Math Only” to a “Tier II – Hardware Plus Math” approach is the optimal strategy for many people that’s available today.
What is a "Hardware Key"?
A hardware key is a small physical security device that functions as an authentication tool for your online accounts…
Hardware keys, such as the Yubikeys below, are lightweight and durable… You can carry a hardware key around with you on a keychain, just like you would any normal key.
The privacy-related benefit of a hardware key is that it adds a real world physical object to a purely mathematical authentication process…
This is a small but critical enhancement to a cybersecurity strategy because hackers cannot “remotely” gain access a physical hardware key.
Indeed, even if (when?) a sensitive online account of yours gets hacked, or if you are the victim of a data breach involving a strong (high entropy) password, this private information is essentially useless without your hardware key.
Your Cryptographic Signature Stored Locally
Hardware keys do not store passwords, instead they utilize public key cryptography to provide a cryptographic digital signature that requires your physical presence (and sometimes a biometrics) to authenticate.
To verify “presence”, you can insert your hardware key into your computer USB port (or use NFC).
Then simply touch the hardware key…
The hardware key will register that you have physically touched it, or that you have registered your fingerprint, before it successfully authenticates.
This is like adding a physical, cryptographic signature to your login process.
By adding a hardware key and requiring local presence (and optionally biometrics) the hardware key eliminates whole classes of remote attacks and remains robust even as cryptography evolves.
This is the “Tier II” approach shown in the diagram below and is the best approach available today.
Do Hardware Keys Help Protect Against Quantum Attacks?
Today’s hardware keys depend on cryptographic methods like RSA and ECDSA, which are potentially at risk from quantum attacks.
While quantum threats are believed to be years away, large-scale quantum computers could one day be able to efficiently break the RSA and/or ECDSA algorithms that underpin the entire world of secure authentication and online security.1
That said, because Yubikeys incorporate the FIDO22 standard, an open passwordless authentication standard that moves beyond the “shared secret” password model and is designed to help protect against phishing and spoofing attacks, they are more quantum resistant than using shared data alone.
FIDO2’s fundamental insight is that decades of authentication problems — phishing, credential stuffing, server breaches, man-in-the-middle attacks — all stem from the same root cause: shared secrets.
By eliminating shared secrets at the protocol level, it makes entire categories of attacks structurally impossible rather than just harder. That’s a qualitatively different kind of security improvement, and it’s why security professionals consider it the most significant advance in authentication in a generation.
Post-Quantum Hardware Keys
Manufacturers such as Yubico are working with organizations like the FIDO Alliance to tackle the challenge of post-quantum hardware keys by creating post-quantum cryptography (PQC) integrations.
In October 2025, Yubico introduced prototypes of hardware security keys that support PQC signatures, designed to withstand quantum attacks while keeping the user’s hardware key authentication experience simple (e.g., a physical touch or tap for authentication).
These prototypes show promise for secure applications, such as safe approvals for code changes or financial transactions, using quantum-resistant algorithms.
Are Hardware Keys More Secure Than Authenticator Apps Like Google Authenticator or Authy?
As shown in the diagram above, the evolution of secure authentication can be broken down into three tiers:
- Tier I: Math Only (strong passwords with or without 2FA)
- Tier II: Hardware Plus Math (A hardware key plus strong passwords/2FA = the best available today)
- Tier III: Post-Quantum Cryptography (PQC)
Using a password only or even two factor authentication (2FA) approach is much more vulnerable today, even without the quantum threat.
By incorporating a hardware key into your authentication setup, you are increasing your security resilience.
Why are hardware keys (or passkeys) an upgrade over using a traditional 2FA methods, such as SMS or an authenticator app?
- Phishing resistance: This is where the gap is most dramatic. When you type a temporary one time password (TOTP) code into a website, nothing stops you from typing it into a fake website. A convincing phishing page can capture your code in real time and replay it within the 30-second window — this attack is common and well-documented. A YubiKey refuses to authenticate if the domain doesn’t match the one it was registered with. This is baked into the FIDO2 protocol. You physically cannot be phished with a hardware key in the way you can with an authenticator app.
- No secret to steal remotely: TOTP works by sharing a secret seed between your authenticator app and the server at setup time. That seed lives on a server database. If that database is breached, an attacker can clone your authenticator entirely — without ever touching your phone. Because your hardware key’s private key never leaves your hardware device, there is no server-side secret to steal.
- No man-in-the-middle vulnerability: A sophisticated attacker could sit between you and a real website, forwarding your TOTP code in real time while impersonating the site to you. Hardware keys cryptographically bind the authentication to the exact session and origin… As such, a replayed or intercepted credential is basically useless.
- Physical presence is required: An authenticator app can be compromised remotely via malware installed on your phone, SIM swap attacks on SMS-based backup codes, or cloud backup vulnerabilities… Both Authy and Google Authenticator offer cloud sync, which widens the attack surface. A hardware key requires the physical object. Remote attacks simply don’t work.
Hardware security keys that feature biometric authentication (such as fingerprint scanning) and require physical presence (like USB insertion, NFC tap, or a touch confirmation) are being updated to counter quantum threats.
Devices like advanced FIDO2-compliant keys with integrated cryptography and biometrics improve security.
Can Quantum Computers Forge Biometric Signatures?
Hardware keys that utilize biometrics and physical presence are being designed to be resistant to quantum threats. This is done by replacing classical cryptographic algorithms, such as Shor’s Algorithm, with PQC standards approved by NIST, including:
- ML-KEM (based on CRYSTALS-Kyber for key encapsulation), and
- ML-DSA (based on CRYSTALS-Dilithium for digital signatures)
These new algorithms are built to withstand attacks from quantum computers running Shor’s algorithm, which can factor large numbers and solve discrete logarithms to break standard public-key cryptography.
New hardware key designs are needed to accommodate larger key sizes and computing requirements of PQC algorithms, which do not fit on current keys.
Beta testing for signing functions is in progress for select users, but broader use relies on finalized standards from organizations like NIST, FIDO Alliance, W3C and IETF.
Biometrics add a further layer of security by using “match-on-device” technology, which stores and verifies fingerprint templates locally on the key, minimizing exposure. This setup supports zero-trust models and prepares for upcoming regulations like the U.S. CNSA 2.0 focused on quantum-resistant systems.
Hardware Keys Are More Quantum-Resilient, But Not Quantum Secure
Biometric “signatures” are digital templates from physical scans, matched using algorithms that factor in variability like angle or pressure.
Forging them generally involves physical manipulation (such as creating fake fingerprints) or access to the sensor rather than just computational capability.
Quantum computers cannot forge biometric signatures directly as they can with cryptographic signatures, because biometrics are based on physical traits (like fingerprints or facial features) instead of mathematical algorithms.
Nonetheless, quantum computers present indirect, if remote, risks because the attestation (i.e. the signal, message or “handshake” between your hardware key and the 3rd party confirming that physical presence was confirmed, authentication was confirmed, etc.) are digital…
Also, if biometric templates are stored in a digital database that is hacked, or transmitted using quantum-vulnerable encryption (like RSA), a quantum attacker could, in theory, decrypt them using Shor’s algorithm and attempt to replicate or spoof the biometric data. For instance, quantum-enhanced attacks could expedite brute-forcing or generating fake biometric templates.
As such, the cryptographic layer must be quantum resistant along with a physical presence requirement to be truly quantum safe.
Summary
Quantum computers excel at breaking math-based cryptography but face challenges with physical elements like biometrics…
As such, hardware keys with physical presence requirements are the best authentication option available to home users today.
Consider using a hardware key, such as Yubikey, for a more quantum-resilient approach than any alternative in common use… Hardware keys will become fully post-quantum secure once algorithm upgrades are deployed, but they are still a cybersecurity improvement now.
If you’re worried about long-term threats, keep an eye on updates from Yubico and consider hybrid strategies (e.g., mixing with symmetric encryption like AES, which is more resistant to quantum attacks through Grover’s algorithm but needs larger keys).
For the moment, hardware keys remain essential tools for everyday security.
Footnotes
- Some hackers utilize a "harvest now, decrypt later" approach. Consequently, static hardware keys would not inherently be a safeguard against future quantum threats, as their underlying cryptographic signatures may be broken once powerful quantum computers emerge (anticipated in the coming decades).
- Developed by the FIDO Alliance and W3C.
