https://news.ycombinator.com/item?id=8106721
https://news.ycombinator.com/item?id=4254925
edit: added sources
https://news.ycombinator.com/item?id=8106721
https://news.ycombinator.com/item?id=4254925
edit: added sources
The most effective thing the NSA could do to weaken Signal is fund people to spread FUD about it on message boards and drive people to inferior solutions. I'm not saying they're doing that, but it would be way more effective than providing funding to an open, peer-reviewed protocol and implementation.
In terms of cryptographic robustness, it's good for an app like Signal to have a closed-source server, because it forces you to not trust the server.
(This is of course separate from whether it's good for the Signal server to be free software for inherent free-software morality reasons.)
Still, I think the most important breaches of privacy are not necessarily in decoding the messages themselves, but rather everything from location data to contact lists including time and number of communications these apps have access to by default.
I lost an semi-important document that was shared with me over skype because of that.
First, you'll want to make sure Skype is set to keep message history forever: Skype -> Privacy -> Keep history for... -> Forever
Then, you can right-click on a contact -> View Old Messages -> 1 Year, etc.
This is assuming you're using Skype, and not Skype for Business; they are not the same: https://en.wikipedia.org/wiki/Skype_for_Business
I don't see any evidence that the OTF is a front for the NSA, or that you think somebody with the capability to make that in a year would sell their soul for $455,000.
(Yes, technically, a keyed "backdoor" would work and allow the NSA alone to hold the corresponding private key, but also Signal's client code is public so there isn't really a place to put one of those without anyone noticing.)
That's not really a sensible way to describe either their officially stated or inferred mission.