TL;DR: Is there any difference between an authentic and a secured website? More precisely, is there any security benefit to be connected to a website via HTTPS if the certificate isn't valid?
Following a test I had today where we was asked if it was better to be on a secured website or on an authentic website when browsing on a shopping website, I wondered if there was any difference between secured and authentic.
IMO, by definition, an authentic website has to be secured, otherwise any authentication of the website would be meaningless.
But then, is it true in the other way? Is a secured website necessarily authenticated? Can we still consider that you are using HTTPS and that there is a security benefit to it if the certificate isn't valid?
From my personal understanding, while a "non-authenticated asymmetrically secured connection" will be less secured than an authenticated one, there is still the benefit that as long as no man in the middle attack occurs, nobody will be able to decode what was transmitted, am I right?