• booly@sh.itjust.works
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    4 months ago

    One time pads are perfect encryption, but the problem is that the key length needs to be longer than the message length. So if you have the ability to get the symmetric key to the recipient securely, then you had the ability to get the whole message to the recipient securely.

    • robojeb@lemmy.world
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      4 months ago

      One time pads aren’t really feasible at scale. Getting the pad (key) to your partner securely will involve moving it in meatspace.

      If you tried to send the pad with some other encryption that becomes the weak point and defeats the pad.

      You can’t reuse the pad for multiple transmissions or you are vulnerable to analysis attacks.

      You can’t compress the pad and send it with remaining space of a previous pad because the pad has to be true random numbers and won’t compress well so you will always come out behind.

      They are great in theory, and in practice for a few fixed short form communications in emergency situations but I don’t know of any practical way they could be used generally. Your bank isn’t going to ship you a hard drive of random numbers for you to securely look at your account.