Over millennia, mankind has used hard cash in various forms ranging from shells to gold coins and paper. More recently, cash has become unpopular in political circles, as it effectively restricts states’ power to tax (explicitly or via negative interest rates) or to survey and potentially...

Digital payments and decentralized systems enable the creation of new financial products and services for users. One core challenge in digital payments is the need to protect users from fraud and abuse while retaining privacy in individual transactions. We propose a pseudonymous credential...