I searched for this feature request in this forum but didn't see it. Do you think it's a good idea to include contacts in Joplin and integrate with Android?
There aren't many encrypted contact services. Protonmail is well, but I couldn't directly use it on my phone. etesync provides this service but for a fee, and they host the data on their server.
Would it be possible to host end-to-end encrypted contacts on a cloud provider of my choice with Joplin, and use it on Android without importing them to my phone? My contacts can be stored on my server end-to-end encrypted. So as long as I log out from Joplin, there are no traces of my contacts
You could of course put every contact in a new note with E2EE turned on, but I can't see a way to integrate contact information with other apps in a meaningful way (such as phone or mail apps).
If I understand you correctly, it would be the best solution to self-host a Nextcloud server and access your contacts via CardDAV on your phone using Android apps such as DAVx5.
Edit: just read your last sentence - that seems to be tricky indeed. Proton Mail and Tutanota offer something of that kind (as you mentioned), but encrypted (and fully functional) contact info seem to be a difficult issue even for privacy-oriented services like these.
Joplin stores notes, that you have read, on your device. It’s because they are downloaded for reading and not deleted afterwards. And this is a feature, not a bug So in your example, every contact you open has been downloaded before.
AFAIK there is no way to only read notes „online only“ like in a browser
And these notes on your phone are not encrypted by Joplin…(there are tons of threads here discussing encryption on devices…)
So in your example, every contact you open has been downloaded before.