How does password encryption protect against man in the middle attack?

Question

So say Eve wants to steal my email account, but I know that so I encrypt my password before sending it in a way that only I and the email provider knows how to decrypt. What prevents Eve from just copying all the bytes I send and send them as they are to login?

In: 18

Answer 1

Diffie Hellman key exchange is very clear that you could. But you need to do a lot of calculations to do so. It just gets too expensive.

Textbook are using colour mixing as an example. It is easy to mix colours, but very hard to unmix them.