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I don't like passkeys

853 points · 819 comments · ethanhawksley

  1. drtz · · focus · HN ↗
    Passkeys do marginally improve security against MITM and phishing attacks, but they are primarily for protecting the lowest common denominator from themselves: people who re-use passwords and/or don't use a password manager.

    If you use multiple devices throughout the day, registering passkeys in all of these systems becomes a big headache with O(m*n) complexity, so putting the passkeys in a password manager is the only realistic solution. But this still breaks the login flow for a very common use case: how do I log in on a device that I don't own? With a password in a password manager I at least have the option of manually typing the password.

    The biggest problem, though, is how users are pushed into it without any warning or knowledge of what they're signing up for. I've accidentally set up passkeys just by clicking an okay button a few times in the past and had to go back and figure out how to undo it after being blocked from login on another computer (which computer was I on again?).

    1. judge2020 · · focus · HN ↗
      > how do I log in on a device that I don't own?

      This is solved by passkey-implementing software and devices (with Bluetooth) allowing you to log in with a QR code (Webauthn via CTAP hybrid transport). iOS and Android support this, and it’s generally not a locked-down thing if other devices wanted to do it too.

      The only use case left is in “how do I login if all my devices are stolen/fall into a body of water” in which there really isn’t an answer beyond “get (a|your) device back, sign back into your password manager, use that to get back into critical accounts”.

      1. 201984 · · focus · HN ↗
        What if the computer you want to log in on doesn't have Bluetooth? Probably most public computers (like ones in libraries) don't have it.
        1. limagnolia · · focus · HN ↗
          The website should display a qr code you can scan with your phone that allows you to then login, unfortunately a lot of sites don't implement this, and some don't implement backup codes. This isn't the fault of passkeys per se, but of poor implementations.
          1. 201984 · · focus · HN ↗
            How does scanning the barcode with your phone log you into the computer? Does your phone need network access for that?
            1. roryirvine · · focus · HN ↗
              If you're not happy connecting your phone to the network, then how likely is it that you would you be willing to enter your login details on a machine you don't control?
              1. tavavex · · focus · HN ↗
                What if you just can't have internet on your phone? Like if the computer is connected via Ethernet and there's no wifi network you can connect to? What if you're abroad and have no roaming? And the ultimate question about a person that the modern world can barely conceptualize - what if you have a dumbphone? Or what if your smartphone is lost or stolen or dead and you need to access some account? That last one has happened to me, and I sure am glad I know the key passwords that I need for survival.

                These may seem like nitpicks, but there's probably a thousand rare scenarios like these that exist. You inevitably have to consider them when you're moving from punching in letters and numbers that you remember in the normal, low-tech way to a complex networked two-device workflow.

                1. nightski · · focus · HN ↗
                  You can consider them by keeping a password. Bam done. Don't ruin the auth experience for everyone else because of niche scenarios.
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