cralder, 1 year ago

You are describing symmetric encryption where both parties have the same key. There is something called asymmetric encryption that solves this. Basically you have a public key and a private key. You can give your public key to youtube, they can use that key to encrypt the symmetric key that will be used for the actual communication. The only way to decrypt the symmetric key is by using your private key, which is only known to you. So youtube can safely send it to you so you can decrypt it. Now you both have the same key and nothing was sent unencrypted.

Well your public key was sent unencrypted but that’s fine because of how asymmetric encryption works.