New Pass-ta-key attack reveals all the things we didn’t know about passkeys
A researcher recently described a "Pass-ta-key" attack capable of extracting all passkeys stored in Google Password Manager on a malware-infected Windows machine, prompting concern that passkeys might not be as secure as claimed. However, the technique is neither novel nor unique to passkeys, and the confusion stems from a widespread misconception about how passkeys are actually stored, rather than a genuine new flaw in the technology.
Contrary to popular belief, FIDO2 specifications do not require passkeys to be kept in dedicated secure hardware such as a trusted platform module (TPM); in practice, only Microsoft offers TPM storage, mainly for enterprise users, while all other platforms store passkeys locally to allow syncing across devices. This is generally considered safe because strict app permissions on macOS, iOS and Android prevent malware from reaching stored keys without an OS-level exploit. Windows is the exception, since its apps typically run with full user privileges and its sandboxing only blocks access in one direction, leaving locally stored passkeys more exposed to malware on that platform specifically.
- "Pass-ta-key" attack targets Windows Google Password Manager passkeys, not passkeys generally
- FIDO2 never mandated hardware storage; most platforms store passkeys locally
- Windows alone lacks robust sandboxing, making local passkey storage riskier there
Both sides, in good faith
The strongest fair case each way — we don't pick a winner.
The case for
The attack reveals that passkeys, despite promotion as more secure authentication, remain vulnerable to malware on Windows—the most widely used desktop operating system. Even if the technique exploits implementation choices rather than the technology itself, the practical effect is that users expecting enhanced security may find themselves at risk. The inconsistency across platforms suggests passkeys have failed to deliver uniform protection, raising legitimate questions about their readiness as a universal password replacement.
The case against
This attack demonstrates not a flaw in passkey cryptography or the FIDO2 standard, but rather a consequence of intentional design trade-offs: storing keys locally to enable cross-device syncing necessarily exposes them to malware on platforms with weaker sandboxing. The same vulnerability would affect any locally stored credentials, including recovery codes. Passkeys remain fundamentally more secure than passwords because they resist phishing and are cryptographically sound; the Windows malware scenario reflects platform architecture, not evidence that passkeys themselves are insecure.