The feature was rolled out in November.
Signal, an encrypted communications app, has let users send the cryptocurrency MobileCoin to other users around the globe for months. The company released the feature, still in beta, to users in November without any notification.
"MobileCoin's technology is encryption for blockchain commerce," MobileCoin CEO and founder Joshua Goldbard said. "Just like e-commerce required the development of SSL, blockchain commerce requires end-to-end encryption of the ledger. MobileCoin is the solution that protects consumer and business financial privacy."
"Information about the transaction is private: Sender, receiver, amount transferred, and message are all unknown to Signal," according to Signal.
Signal users must opt into the beta from their settings page. All fees are collected by MobileCoin, and MobileCoin may charge some users a Coin Cleanup Fee if their coins can't be combined to complete a transaction.
CNET has reached out to Signal for comment.
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