Central banks control the circulation and supply of money globally, but the phenomenal rise of cryptocurrency poses a threat to their authority, control and power. So central banks around the world are now producing their own digital currencies. In a groundbreaking move for the African continent, buffered by local activity and interest in cryptocurrency — after the U.S., it is the second-largest market for crypto trading — Nigeria joins that list this week. After being in the development phase for the last three years, its central bank is piloting the first digital currency in Africa today. It joins 14 other countries now in the pilot stages with their own central bank digital currencies (CBDCs), including China, Sweden and South Korea, with a total of 81 countries in other stages of exploring CBDCs. Only five have fully launched them : the Bahamas, Grenada, Saint Kitts and Nevis, Antigua and Barbuda, and Saint Lucia. The virtual money, dubbed the eNaira, is backed and issu...