In fact, getting started using Signal's payments feature still isn't quite that simple. “There are over a hundred million devices on planet Earth right now that have the ability to turn on MobileCoin and send an end-to-end encrypted payment in five seconds or less,” Goldbard says, referencing reports of Signal's total download numbers. MobileCoin founder Josh Goldbard confirmed the timing of the rollout, and says that it spurred massive adoption of the cryptocurrency, which now sees thousands of daily transactions versus just dozens before the global beta release.

That's when Signal made the same feature accessible to all of its users without fanfare, offering the ability to send digital payments far more private than a credit card transaction-or a Bitcoin transfer-to many millions of phones. But a much broader phase of that experiment has quietly been underway since mid-November. In the spring of 2021, the encrypted communications app Signal announced that it would add a payments feature in beta for its users in the UK, testing out an integration with a relatively new, privacy-focused cryptocurrency called MobileCoin.

Signal private messaging app