How to protect transmitted data from the provider?

Question

Computer networks

There is a condition that both hosts did not agree in advance on the encryption key for the data transmitted to each other (the only way to communicate is the Internet).
The provider acts as an intermediary when connecting two hosts.
I don’t know for sure, but it seems to me that providers will not store absolutely all traffic, that is, there is an option to transfer the key in a very large file, which is unlikely to be delayed somewhere (in the sense of being saved).
So how to transfer keys to each other through the provider so that he cannot read all the next encrypted traffic after that?
I would like to know options without using asynchronous encryption.

Answer 1

Understand carefully what role a certificate plays in SSL. The certificate is not responsible for encryption.
In other words, there is a mathematically correct way to establish an encrypted connection between two parties over an insecure channel - asymmetric encryption.
The certificate is needed in order to know for sure that such a connection is established with the node that you need, and not with a malicious intermediary.

Answer 2

Ну вы сами отказались от решения в вопросе скорее всего вы балбес

Answer 3

Если правильно понял вопрос, то хотите безопасно передать ключ шифрования? Не сочтите за абсурд, но я бы скинул человеку архив с ключем, а сам архив зашифровал огромным паролем, символов 50-100. Сам же пароль к архиву можно передать по телефону, попросив открыть такую-то страницу такой-то книги и переписав абзац, соотв., предварительно пусть пароль будет абзацем из книги. Если речь идет не о преступлениях против государства и каком-то супер-промышленном шпионаже, то, думаю, способ Вас устроит :)