Signal has the perception of being more secure simply because it isn't owned by Facebook. I will never trust a Facebook server with private messages, despite both Signal and WhatsApp having the same security features on paper.
I refuse to think Mark Zuckerberg
* bought it for north of USD10Bn
* made it free
* stopped all other monetization efforts (paid api gateways etc)
just to provide free messaging service to everyone.
I have two explanations:
* either he felt it was a threat to his future messenging monopoly
or
* (and this is already not a secret anymore) they wanted to feed the data into their already huge tracking and ad serving network.
Both of those are good enough reasons for me to leave as I care about healthy competition and my future privacy.
But maybe the biggest reason why is because they lied to me: they promised to be the service that provided a good messaging service in exchange for a modest fee. They were profitable and yet sold out.
0. https://www.theguardian.com/business/2017/may/18/facebook-fi...
You mean you agree he had an evil plan and it was thwarted?
Well, if you don't consider "being open source" a security feature...
If you are going to audit something for its security features, you pretty much have to start with a disassembled binary, don't you?
In practice, that's unlikely to work, but it could work.