Brazil is taking two different but closely linked steps in the development of its digital financial system. The central bank is looking at ways to connect Pix, the country’s highly successful instant-payment system, with payment systems in other countries. At the same time, it is placing tighter controls on some cryptocurrency transfers, including a new rule that can require certain transfers to be held for up to 24 hours for fraud checks.

Taken together, these moves show how Brazil is trying to shape the next stage of digital finance. The country is not simply replacing old payment systems with new technology. It is building public payment infrastructure that can compete with traditional private networks, while bringing digital…