For cybercriminals looking to launder illicit gains, bitcoin has long been the payment method of choice. But another cryptocurrency is coming to the fore, promising to help make dirty money disappear without a trace.

While bitcoin leaves a visible trail of transactions on its underlying blockchain, the niche “privacy coin” monero was designed to obscure the sender and receiver, as well as the amount exchanged.

As a result, it has become an increasingly sought-after tool for criminals such as ransomware gangs, posing new problems for law enforcement.