As of today, the users of Facebook can find OpenPGP encryption keys in their profile to be able to have encrypted email notifications.
In one Publication, Facebook reports that the new feature is in an experimental stage. Once enabled, users will be able to send end-to-end encrypted email notifications from their Facebook profile to email accounts.
If a user enables encrypted messages, but does not add one key OpenPGP, then Facebook will encrypt the messages using its own key.
At this time, the new attribute can only be managed by computers, not by mobile devices.
"To enhance the privacy of e-mail content, we now have an experimental new feature that lets you add OpenPGP public keys to your profile.
"These keys can be used to 'end-to-end' encrypt notifications sent by Facebook to your preferred e-mail," the company said.
"You can also choose to share OpenPGP keys from their profile, with or without encrypted notifications."
