disclaimer: I’m just asking to get understanding of the theory behind network traffic encryption, I know this doesn’t happen irl most likely.
Let’s take https connection for example. I like watching revolutionary things on youtube and do not wish for authorities to know what I am watching, we accept here for the sake of showcase that google won’t sell my watch history if asked (LMAO what am I even saying?).
So if I’m not mistaken since youtube has https implemented, our communication is encrypted, the keys are shared only between me and youtube. But when Youtube shares the key with me/my client the first time, is that also encrypted? Wouldn’t the same question keep getting answered until there is something unencrypted? I know this is a bit too much unlikely, but if ISP automated the process of gathering keys and decrypting web traffic for a certain site with them for all users, would that work for them?
I’m taking https here as an example, while I have the same question for like VPN.
EDIT: Thank you everybody. I am not a member of this community, but every comment was a golden experience to read!
I think no one has mentioned the base for all the cryptographic functions. A mathematical operation which is simple in one direction but very hard in the the other (backwards). The factorisation of large prime numbers is one example.
I’m satisfied with the answers and insights I got so far. But if you may add I’d be happy to know why factorization of prime numbers is so crucial in cryptography. I heard about this a lot before but don’t know anything. I know quite well about Prime number and theorems about them on math, but not their applications
As I understand it, it’s just as they said:
Calculating primes is fairly straightforward so you calculate a few large prime numbers, and do some math to them.
Now you have a strong key that didn’t require a supercomputer to create but taking that final number and turning it back into those original primes is a much more computationally expensive proposition.
In fact, it’s one that’s not viable with current technology.