Marx might’ve not been the one that coined the term “capitalism”, but he’s for sure the one that popularised it by using it in his papers. And, although he’s (along with his pal, Engels) been widely using it, his framing of the capitalism was just as an intermediate step (a placeholder until the people are ready) towards a more ‘advanced’ society structure — the communism (with a preparation stage in socialism). As such they (Marx and, at a lesser extent, Engels) thought that a lot of the value deriving from a worker’s labour might be captured by various middlemen (in fact just intermediaries that arbitrage the supply and demand within time and space) and that in an ideal society there are very little (if at all), intermediaries. This was in opposition to works of Hayek and later Friedman that praised the role of the middleman (almost considering him the hero) exactly because s/he was taking risks in creating enough supply when (and where) the demand was.
Thinking about the motivation behind the publishing of Satoshi Nakamoto’s “peer-to-peer electronic cash system” paper back in 2008 and the backlash against the bankers — which are seen as responsible for everything that happened then — combined with the fact that banks are, more than often, simple intermediaries between someone that has the money and someone that hasn’t (but has the goods), we might arrive to the conclusion that blockchains are marxist tools.
And if this proves out to be somehow accurate, it might mean that blockchain (and, why not, bitcoin) are essential tools of the socialism, isn’t it? Well that’s one thing that Marx’s ‘Capital’ doesn’t mention.