one time pad

 

In years gone by I was somewhat obsessed with the idea of an unlimited one-time pad encryption algorithm. The idea would be that two people start with a one-time pad but they're able to generate an ongoing one time pad that no one else can figure out and thereby encrypt messages indefinitely that can't be broken. The current basic idea would be that two people share an initial one-time pad. So if they encrypt a message one time and unencrypt it then no one can break that. If they use the one-time pad repeatedly it can be broken.

So the idea is that they start with this one time pad but then they each generate One Time pad that they encrypt against their original one-time pad. Then they encrypt their message against the new one-time pad they generated. Then they send the encrypted one-time pad and the encrypted message in clear text. So this must be breakable somehow, because it just seems too easy. But it is intriguing the idea that you could have an unbreakable encryption that you could just use indefinitely and no matter how powerful the computers get or no matter how much quantum AI you put against it you'll never be able to break it. That's what the One Time pad offers but it's relatively impractical because it requires so much data and you have to be able to physically transfer the one-time pad secretly.