THE BLOCKCHAIN, the technology that underlies bitcoin, has yet to live up to the hype surrounding it. Promising blockchain-based projects, such as a land registry in Honduras, have fallen short of expectations. Ersatz securities listings, called “initial coin offerings”, have attracted unfavourable attention from regulators. Kevin Werbach is a legal scholar at the University of Pennsylvania’s Wharton School of Business and an expert on digital technologies. In the 1990s he was one of the...