Most people have not yet figured out that for the things that are really important, you MUST go low-tech. Anything having to do with software can be hacked. Period. I am a software system architect, saying this.

Currency must be based on tangible assets, like precious metals.

Block chains don't scale well, don't perform well at scale, and are subject to various types of manipulation. Fiat currencies are not much better, but block chain is not the solution either.

So, a US dollar backed by precious metals would be the ideal.