A hodgepodge of boosterish arguments for blockchain technology, “Trust Machine: The Story of Blockchain,” directed by Alex Winter (Bill of “Bill & Ted” fame), is not always a model of clarity, but it does a decent job of explaining the basic concept. Mark Jeffrey, an entrepreneur looking to blockchain for his start-up, describes the technology as a kind of shared, decentralized ledger: “A record of all the transactions, and it’s constructed in such a way that cheating is not possible.”

Bitcoin has its own ledger, and so does every other cryptocurrency. The question that hovers over this documentary, which generally subscribes to the rosy assessments of libertarians and others who view centralization as inherently dangerous, is just how much potential blockchain technology has to do even more.