Passkeys are built on the FIDO2 standard (CTAP2 + WebAuthn standards). They remove the shared secret, stop phishing at the source, and make credential-stuffing useless.
But adoption is still low, and interoperability between Apple, Google, and Microsoft isn’t seamless.
I broke down how passkeys work, their strengths, and what’s still missing
Say you don’t understand passkeys without saying you don’t understand them…
A passkey uses public key cryptography to secure your account instead of a password, it only grants you access to the one account you set it up for, and the account provider only holds your public key, you control the private key. Your passkey is a secure alternative to passwords because you CANNOT reuse it across services, cannot reasonably remember it, and the method of using it isn’t by copying and pasting into a field like a password, so it isn’t susceptible to the same attacks.
If the provider loses your public key, they can’t give you a challenge to verify you have the private key, so you lose access. Just like if they lose your password hash. It’s an identical scenario.
The assumption is that the native passkey manager on the device (iPhone, android, windows) would sync the passkeys (to Apple , Google, Microsoft) for protection against device failure and easy of use across devices. Or you risk loosing your accounts if you loose your device.