Whisper makes Signal and TextSecure for iOS and Android respectively. They're the the best-designed, most trustworthy message crypto available to users today, and one of the only reasons they aren't the global default is that someone needs to take over their front-end and make them the default.
Whisper will pay you less than almost any other company in the Bay Area (they're entirely self-funded) but you'll probably do more good there than you could at any company on this hiring thread, and if you succeed at the job, you'll be an authentic hero for privacy and civil liberties. That's not a bad calling card to have paper-clipped to your resume.
You don't need to be a cryptography expert to talk to them. Also: they're all just fantastic people, some of the best you can hope to work with.
https://whispersystems.org/workworkwork/
I have no relationship with Whisper; I'm just an admirer.