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
    link
    fedilink
    arrow-up
    21
    ·
    edit-2
    1 year 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.

  • panicnow@lemmy.world
    link
    fedilink
    arrow-up
    2
    ·
    1 year 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.

  • sznowicki@lemmy.world
    link
    fedilink
    arrow-up
    2
    ·
    1 year 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).

  • berkeleyblue@lemmy.world
    link
    fedilink
    arrow-up
    1
    ·
    1 year 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
    link
    fedilink
    arrow-up
    1
    ·
    edit-2
    1 year 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