OK - I've updated it > ProtonMail which is a good step, but doesn't let you use your own master key without uploading it*, which complicates things if you requ

OK - I've updated it > ProtonMail which is a good step, but doesn't let you use your own master key without uploading it*, which complicates things if you require the highest level of security. * It will be stored encrypted with your password though. So they never have access to it. Keeping your certification key off the internet entirely is possibly overkill for most users.