Read the whole post: https://www.reddit.com/r/SimpleXChat/comments/1afgrcj/comments_on_comparisons_of_simplex_with_other/
You can also take a look at this paper: Improving Signal's Sealed Sender - NDSS Symposium
Check out this wild topic: Signal stores your decryption key in a plain text file on MacOS
Also this horrible response: Signal for Desktop is Vulnerable to Attachments Exposure | RestorePrivacy