Well, the monetary system itself ticks most of those boxes, it's just very limited in what you can communicate. And it is not perfect either I suppose. In fact

Well, the monetary system itself ticks most of those boxes, it's just very limited in what you can communicate. And it is not perfect either I suppose. In fact there might be significant overlap between something that can support a monetary system and something that supports trustworthy communication. The best you could hope for by solely focussing on communication is that it doesn't collapse under the pressure of having to keep financial transactions secure. Except any secure form of communication is probably going to be used for transactions of some kind at some point.