Another approach at a more general messaging system that can be used to similar ends is Whisper, by the same community that makes Ethereum: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=BrWlAtfqF6s" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=BrWlAtfqF6s</a>