Our great sponsors
-
-
SurveyJS
Open-Source JSON Form Builder to Create Dynamic Forms Right in Your App. With SurveyJS form UI libraries, you can build and style forms in a fully-integrated drag & drop form builder, render them in your JS app, and store form submission data in any backend, inc. PHP, ASP.NET Core, and Node.js.
> Truly secure entity just wouldn't have private keys on a server at all.
They don't. They have your encrypted private key, but there's no need to keep that secret. (The decryption key is derived from your password, so the password needs to be strong and secret.)
> Such agency can force PM to modify login process to derive password from submitted form, or to just switch private keys for non-encrypred ones, because the user won't even notice it.
Yes, definitely. It's hard to trust self-updating software (like JavaScript in the browser), particularly if you're concerned about targeted attacks. But creating your own private keys and then entering them in the browser wouldn't help you at all against that sort of attack. You would instead need a different type of client that could be trusted somehow not to leak your private key.
It's not uncommon for services like this to offer a downloadable version of the web client so you can pin a version and audit the code as needed. I think maybe https://github.com/ProtonMail/WebClient is that for ProtonMail? If so, you should be able to verify that code and then use that. The fact that an encrypted copy of your private key will live on ProtonMail's servers shouldn't bother you.