A review of Offline Payment, a key feature & challenge for Central Bank Digital Currencies

This short (12 pages) document aims at providing the essential information about the challenge of offline payments. Over the last years, offline payments have become a core requirement of Central Banks looking at the creation of retail Central Bank Digital Currency (rCBDC), a digital version of banknotes/coins, directly issued by the Central Bank for use in the day-to-day exchanges between economic actors.