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Diffi-Hellman is actual magic. You can exchange keys over an unencrypted channel and end up with guarenteed unique keys, on which you can start a secure channel

Like how??

Comments
  • 2
    oooh I was looking for something like this

    yooink
  • 2
    Not necessarily unique. But yes, DH indeed is cool!
  • 8
    DH is just taking advantage of asymmetric encryption keys. The real magic is those keys in the first place...

    I can literally give you a key that allows you to encrypt a message that only I can read because I know a completely different key that I never told anyone.

    EDIT: I do like the ratcheting alternatives a lot though, very clever stuff as well
  • 4
    Funnily enough, you can even make it a shared key with multiple participants. You just have to run it in a circle. A chat with 30 people? No issue, just run it from person to person. It is amazing. Shared secret. Anyone listening? No issue.

    I think that's often overlooked, but Diffie Hellman can make a key with n>=2 participants. My favorite feature!
  • 1
    @TrayKnots scuse me while I go google. 2 participants makes intuitive sense, need to go read about this. Interesting!
  • 1
    OK but like... Why not just set up 5 2 way exchanges instead? I guess to verify that everyone got the same message.
  • 2
    @atheist

    I think they do 5 2-ways. It is easier and imagine a group chat. Easier to hand out the old key or maybe make a new key if old messages should not be shared than waiting until everyone had been online at least once with the last person online.

    I just think it is neat that it is possible. And there will be probably some cool use cases. Like common key for systems that are not in real-time communication? Like a letter system? Don't forget you can always send it home early.

    Like 1-2-1

    And then just act like that hasn't happened and make it 1-2-3-1. And so on. Might be a cool way to solve a problem with lightspeed delay?
  • 1
    Until yet another idiot decides to stand up and think for a while instead of learning crap at school, writes some simple equation and push forward entre civilization by thousands of years.

    It’s just temporary solution that works because of science stagnation.
  • 0
    @tosensei

    Correct, it's just math. But math is magic, though.
  • 1
    @tosensei

    I am with you that magic is advanced technology. But an equal sign. Not a direction.

    Also math. Fucking hell, math is magic. What you can reason from betweenness of graphs or statistical analysis of problems.

    How many bears are there... Hmm.. Let's catch a bear, mark him with color, release him and then start catching bears until we catch our marked bear again. And we have a pretty good idea of how many bears there are.

    I raise my child knowing that if she goes to uni and chooses natural science of any kind, she essentially goes to Hogwarts. Magic is real. Wanna be a witch? Study math and sciences!
  • 0
    @tosensei No, it’s still pretty magical.
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