New Pass-ta-key attack reveals all the things we didn't know about passkeys

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Security researcher Arie Olshtein at Palo Alto Networks demonstrated 'Pass-ta-key,' an attack that extracts all passkeys stored in Google Password Manager for Windows from a malware-infected machine. This surprised many users who assumed passkeys resided exclusively in the device's Trusted Platform Module (TPM) — dedicated hardware for cryptographic secrets.\n\nThe reality, as Ars Technica explains, is that most platforms store passkeys locally in software, not dedicated hardware. The FIDO2 specifications do not mandate TPM storage. The shift to software-based local storage was a deliberate choice to enable cross-device syncing: passkeys locked in a TPM cannot be synced to new devices without re-creating each one individually. Only Microsoft offers the option to store passkeys in the Windows TPM, primarily recommended for enterprises.\n\nThe practical implication: on malware-infected Windows machines running Google Password Manager, all passkeys can be extracted. Ars Technica frames this as 'mostly a nothingburger' because it requires existing malware access — the same threat model that already exposes passwords, session tokens, and other credentials.\n\nFor enterprise security teams, the key takeaway is that passkey security depends heavily on platform choice. Windows TPM-backed passkeys (Microsoft's recommended option for enterprises) provide a higher assurance level than software-based alternatives.