@Mer__edith I mean, look at Molly, a fork of Signal on Android that also encrypts the shared preferences XML file, while regular Signal does not.

Signal is both a security and privacy-focused instant messenger. It should encrypt even banal things such as preferences, and shared images, video, media. You're clearly not out of options, and you should provide the encryption for the attachments, because from reading the comments here, it's very much possible.

(github.com/mollyim/mollyim-and)