SelfSovereignty please stop making claims about technical things that you very clearly don't have a clue about, it is getting extremely annoying. Privnote is not anywhere near as secure as GPG. For one they could backdoor the code just like you said. For two you need to transfer the URL in plaintext or encrypt it with GPG, opening it up to massive MITM potential. The fact that a message is deleted automatically doesn't mean jack shit since somebody who does MITM will just intercept , read, make a new message. GPG is for getting around issues like that, privnote doesn't do jack shit to solve the underlying issues. Not to mention it is written in javascript, which is hardly the ideal language for doing crypto shit in. Not to mention you have not even looked at the code so how the hell are you to know if it is secure or not? Oh not to mention when you use privnote you are weak to your Tor exit node sending you a bugged version of the javascript client.