It should be noted that Charles Stross wrote a book, Neptune's Brood, where a bitcoin-like currency is used to finance interstellar colonization, so a lack of vision is not really a problem.
The gist of it, if I remember it right, is that all transactions are authenticated by an interstellar 2-phase commit handshake. The distances involved keep the value of the currency stable, because transactions can take decades to process, and the direction of the signal is actually used as a form of authentication, to guard against (literal) MITM attacks. The goal of slow money was to have a currency that was stable enough to finance multi-century interstellar colonization projects.