Let’s start with a smartphone. A user creates an account with a passkey for a service, that passkey gets stored on their smartphone, and they can use biometrics to sign in from then on. The private key is stored on the smartphone. Great.

But then how do you sign into that same service from a different device?

If it’s by using a password manager, some third party piece of software, How do you sign in on a device where you’re not allowed to install third party software?

  • credo@lemmy.world
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    2 years ago

    How do you sign in on a device where you’re not allowed to install third party software?

    You don’t. Passkeys are very ecosystem-centric right now. If you are in apple, google, or Microsoft entirely, they will all allow you to move your passkeys around to different systems using the same basic mechanism they used for password keeping. Moving across ecosystems is absolutely broken - or rather - has never worked.

    I think there are mechanisms to allow passkeys to work via Bluetooth or even via camera, as an external authenticator essentially, but I’ve never personally tried them.

  • sznowicki@lemmy.world
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    2 years ago

    Service shows you a code that you scan with your device. This code transfers some challenge and information where to send a response. Your device checks if you’re you and then sends a response telling the server you try to log in that hey this guys is indeed the guy, here’s the problem I solved using my private key (asynchronous encryption).

  • 👍Maximum Derek👍@discuss.tchncs.de
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    2 years ago

    I use 1Password as my Passkey holder so it’s device agnostic. But if 1Password ever pulls a LastPass, it won’t seem like a clever solution anymore.

  • panicnow@lemmy.world
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    2 years ago

    Depending on the site, you can use one device to login to another without installing additional software. For instance, if you have an iPhone with a passkey for microsoft.com stored on it, you can login to Microsoft.com using the iPhone.

    Here is a webpage that has some screenshots to show you what I mean. You can probably google some other examples.

    https://appleinsider.com/articles/24/05/02/microsoft-finally-lets-users-sign-into-accounts-with-passkeys

    It is possible to sync passkeys across devices but at this point is mainly within a single ecosystem.

  • berkeleyblue@lemmy.world
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    2 years ago

    Passkeys should display a QR Code for you to scan with a trusted device if you try to use them on a device that doesn’t have your passkey stored.

  • Everythingispenguins@lemmy.world
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    2 years ago

    I would really recommend never using bio metrics on your phone regardless of the context. It is easier to fake that you would want it to be. Also you are legally allowed to not tell the law your password. But they can take your biometrics by force.

    Edit people really love their biometrics lol

    • Em Adespoton@lemmy.ca
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      2 years ago

      I’ve got a pair of YubiKeys that I use to back my passkeys. Works great; I’ve got passkeys that work within the Apple, Microsoft and Google ecosystems and don’t have to worry about password prompts for the most part — but I DO need a YubiKey handy to validate that it’s actually me at the device.

      My keys use both NFC and USB-C and work across all my passkeys supported devices when I add in a USB adapter.

      One spends most of its time in a safe deposit box, and the other lives on my physical keychain.

      To use it, the person would need to be logged in on a device I own (that’s password protected) AND have one of the keys (which also requires a PIN).

        • Em Adespoton@lemmy.ca
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          2 years ago

          Definitely. Costs extra, has an extra step to set up, and has an extra step to use, but is so much more secure.

          That said, biometrics are better than “1234”. I have no issues with people who have bad password hygiene moving to biometrics, which at least add an extra barrier for account compromise.

          But for the rest of us, physical security tokens are definitely the way to go.