(signal.org)
We want payments in Signal to be fast, private, and work well on mobile devices. The first payments protocol we’ve added support for is a privacy focused payments network called MobileCoin, which has its own currency, MOB.
Signal Payments makes it easy to link a MobileCoin wallet to Signal so you can start sending funds to friends and family, receive funds from them, keep track of your balance, and review your transaction history with a simple interface. As always, our goal is to keep your data in your hands rather than ours; MobileCoin’s design means Signal does not have access to your balance, full transaction history, or funds. You can also transfer your funds at any time if you want to switch to another app or service.
Welp, It's really a shame that Signal is heading this way. Cryptocurrency and blockchain are overhyped and unproven and this will make it even more difficult to recommend Signal now.
I feel the matrix protocol is truly the way to go for encrypted, decentralized, and open source messaging.
Signal testing in-app payments in the UK using blockchain and cryptocurrency