‹ BackHN Continuity

Thread

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. limagnolia · · focus · HN ↗
                  If my phone is lost or damaged, I would buy a new, cheap Android phone and sync my passkeys to it. But I am curious why one would need to login to a website in order to survive? If one did have say a severe medical condition that somehow required a website in order to manage, I guess I would concede that maybe passkeys aren't the best way to secure such a life-sustaining website.
                  1. horsawlarway · · focus · HN ↗
                    > But I am curious why one would need to login to a website in order to survive?

                    They use bank like Ally or Discover with no physical branches.

                    They use a mortgage provider like Rocket mortgage with no physical branches.

                    They use a medication delivery service with no physical customer facing pharmacies.

                    They have an employer that only facilitates reimbursement for expenses via online tools.

                    etc...

                    I guess "survive" has a sliding scale, but if I lost access to critical accounts... my life is going to FUCKING SUCK in a non-trivial and very impactful way almost immediately, on many fronts.

                    And if your answer to that problem is "well, just call them"... then we're right back to the point the article is making: "An account’s security is still dictated by the weakest recovery method"

                    Passkeys aren't a meaningful improvement in security - assuming you do actually have decent password hygiene like a password manager.

                  2. epihelix · · focus · HN ↗
                    If your phone is lost, how are you going to sync your passkeys to your new cheap android? In a passkey-only future, you cannot login to your Gmail account without your passkey, which is only on your phone, which you've now just lost.

                    What am I missing? Either we retain passwords as backup for a lost or stolen device - in which case, all the security concerns are still there - or we only use passkeys, in which case we've added a clear nonrecoverable point of failure in the system.

                    1. AlienRobot · · focus · HN ↗
                      What confuses me is that for a long while we told people to not write their passwords on a sticky note, to not write them in plain text somewhere.

                      Then we introduce all these "security" mechanisms that make it literally impossible to recover an account without backup codes.

                      Where do you store the backup codes? The average person, if they store it at all, will store it on a plain text file or in a sticky note.

                      Except that this creates a much more brittle system. Systems are safe when they are routinely tested/used. If you routinely have to enter your password, you are aware you need it. If you don't need your password, and you never have to enter your backup codes, you won't feel the importance of them until you actually need them.

                      It's the whole "I have backups" vs. "the backups actually work" problem except it's pushed onto the users who have zero technical knowledge.

                      1. dwaite · · focus · HN ↗
                        FWIW my break-the-glass actual use of backup codes is for access to my password manager.

                        Everything else which has ever given me a backup code... gets stored in a secure note in my password manager.

                        It is just another knowledge-based factor. It is one that they are reasonably sure you aren't spreading around the internet. It is one that the site gets to pick rather than the user. But in reality, they are a often just a way to try to reduce some support and identity verification costs.

                        The path to get to the password manager is the case where the backup codes truly matter, because without them there may not be a way for support to restore access. Those codes may be your only way of regaining the master encryption key.

                        But that also winds up being part of the trade-off of security vs user friendliness. Some password managers are way easier to get back into.

                  3. tavavex · · focus · HN ↗
                    Doesn't being able to sync your passkeys by entering your conventional password somewhere eliminate the whole point of passkeys? It just shifts the point where you can enter the password to recover your data to a less convenient place.

                    When I said "survival", I meant it in the "being able to make do with few resources in a time of crisis" way, not that you will literally die if you can't access an account. Losing a crucial device without a fallback of being able to log in somewhere else quickly can mean immediately losing access to payments (the most crippling, especially if you're not home), being stranded in an airport or even not having an identity document (in countries with digital ID systems). Any of these happening can lead to enormous losses in time, money or quality of life, depending on when and where this event hits you.

Open on Hacker News to reply ↗

Unofficial Hacker News client; not affiliated with Y Combinator.