Just a random thought experiment. Let’s say I have my account on a lemmy instance: userA@mylemmy.com. One day I decide to stop paying for the domain and move to userA@mynewlemmy.com, and someone else gains it and also starts up a lemmy instance.

If they make their own userA@mylemmy.com, how do federated instances distinguish who’s who?

Have I misunderstood the role of domain names in this?

  • Vlyn@lemmy.mlEnglish
    1·
    1 year ago

    You still don’t seem to grasp the issue I’m pointing to.

    You have instance 1, lemmy.whatever, this instance federated content to lemmy.ml. So now lemmy.ml holds content from lemmy.whatever.

    Instance 1 gets nuked. Either because someone stole the domain, or the admin simply lost the private keys and had no backup. Or they had a backup but it’s old and half their users got lost. A new Lemmy instance gets set up on lemmy.whatever (with a new key obviously). This is Instance 2.

    Now lemmy.whatever starts federating content to lemmy.ml, but from instance 2.

    How do you differentiate content and users from instance 1 and instance 2? It’s the same domain, but different instances as the keys don’t match. Do you block instance 2? Do you delete everything from instance 1 and now instance 2 is the “true” instance for the domain lemmy.whatever? Do you mark all new content from instance 2 as “unverified”?

    Sure, with private keys in place a user test@lemmy.whatever from instance 2 can’t modify content from the instance 1 user test@lemmy.whatever. But the instance 2 user could create new content under the name of the old user. How is this federated? Do other instances show the guy as test(2)@lemmy.whatever because the keys don’t match?

    • 𝘋𝘪𝘳𝘬@lemmy.mlEnglish
      1·
      1 year ago

      You have instance

      Let’s stop it here. Instances are completely irrelevant in my idea.

      but different instances as the keys don’t match

      *sigh* The keys are in the Actor objects and in the Action objects and not in the instance. You cannot validate any instance, you cannot validate if an action was performed on a specific instance. You cannot prevent actors of the same name after the previous instance was wiped.

      All you can do is validating if an action was performed by an actor existing at the time the action was perfoed and that both were signed with a specific key.