[roastedpeacock]

Even if the attacker cant decrypt existing e-mail the concern is by hijacking the account they can intercept future e-mail received such as password resets.

Some searching finds this comment. [1] I would be interested if such a password reset were possible against someone who for instance had 2FA enabled, no recovery information and only accessed their account using the Tor onion-service. ;-)

[1] https://news.ycombinator.com/item?id=19367063

[WhackyIdeas]

Tor onion service relays are mostly on VPS. And those VPS are mostly American.

The number of tutorials I have seen about spinning up a tor relay on a VPS is crazy. These tutorials are probably written by three letter agencies - though I have no proof.

Regardless, protonmail doesn’t let people register when connecting with Tor unless you use phone number or card to make a payment. You will have to give up something which identifies you, and so it really doesn’t matter when you connect with Tor after you have already registered - there is a way to connect who you are.

[roastedpeacock]

Traffic of onion-services is encrypted. Traffic correlation to deanonymize the client can still be theoretically performed but ultimately you need to draw the line in the sand somewhere.

> Regardless, protonmail doesn’t let people register when connecting with Tor unless you use phone number or card to make a payment

Actually if you attempt enough times you will get the option to verify the registration with an e-mail. And they are rather liberal with which options they accept. So it is not exactly a circular dependency.

From there is it an exercise to the reader to create an account not linked to any other identity.

[ivan_gammel]

Valid point, however that happened at least 5 years ago. Proton was smaller. I don’t know if this is still the case for today: I would expect that they continuously improve security of user accounts as they grow.