There comes a time in every hyped-up business trend’s life cycle when the noise becomes so intense it’s comical. Cryptocurrency, bitcoin, and most important, the blockchain technology that underlies them, have reached that moment. Executives in just about any industry imaginable—music, advertising, medicine, pizza delivery—are now eager to discuss how they can capitalize on “the blockchain.” (Note to execs: There are many blockchains, not just “the one.