But to Warren’s dismay, US officials were largely steering clear of any real oversight as crypto expanded its influence.

“There’s been a kind of run-for-cover sense among the regulators, who hope that if they just hide out long enough maybe it will go away,” Warren told the Globe. “Cryptocurrency is not going away.”

That realization has finally taken hold in Washington and led to growing support for what could be the killer app for this new private digital money — an official digital version of the dollar minted not in the Treasury but solely online.

It would be the biggest change to US currency in a century.

While much of today’s money is effectively digital — think direct deposit paychecks, credit and debit cards — using it requires a bank or payment app like Venmo to process the transaction. A digital dollar would be issued directly by the nation’s central bank, the Federal Reserve, and like cryptocurrencies would eliminate the middleman, allowing for lightning-fast check clearing, no-fee payments, and other unforeseen innovations that Neha Narula, director of MIT’s Digital Currency Initiative, recently told Congress “could do for the transfer of value what the Internet did for the transfer of information.”