I don't like passkeys | Ethan Hawksley

I feel like there’s some potential in password-derived passkeys, which would get around the storage and hardware lock-in issues. It’d essentially be a master password like for BitWarden, but instead of needing an app to store a bunch of generated passwords, the master password could be all you need to authenticate.

Most of the sources of compromise for regular users would be eliminated because the password never leaves the client.

So…re-using the same password for every service and site?

Grandma, that’s enough internet for today, OK?

In the scheme I’m proposing, the password never gets sent to the server.

The issue of password reuse is the password getting sent to the site, because the prevailing approach is to hash the password server-side. Passwords leak because they get stored in plaintext, or hashed using outdated algorithms, or get logged with request metadata–bottom line, they end up stored somewhere that an attacker can get their grubby little paws on them, or in a way they can reasonably recover them.

Using a master password to derive a passkey client-side isn’t any different than using a master password to unlock a password manager. It just cuts out the middle step.