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.
This is not true. In key pair cryptography, the public key used only for encryption and the private key is used only for decryption.
As far as I understand a key pair can be used bi-directionally like I’d described. Was I mistaken?
In practice, the private key is usually used to create signatures instead, but I avoided that for simplicity.
no, it isn’t bidirectional, public = encrypt, private = decrypt, that’s it. You can address a message to multiple recipients though (when using GPG), so often in case of email a message is addressed both to yourself and your recipient, so both you and your recipient have access to message text
You’re not mistaken, it is definitely possible with at least RSA, though, I would guess it may not always be possible. It also sounds like it’s still a bad idea unless you know all of the parameters used to generate the keys and can be sure what information is actually encoded in the keys.