According to Reuters, a former Bank of Japan executive said on Wednesday that the challenges posed by Facebook's Libra cryptocurrency may prompt central banks to study the possibility of issuing their own digital currencies. The central banks of the United Kingdom, the Eurozone, Japan, Canada, Sweden and Switzerland announced on Tuesday a plan to share and study the possibilities and experience of issuing digital currencies. The current debate about the future of currencies is becoming increasingly fierce. Hiromi Yamaoka, former head of the Bank of Japan ’s department responsible for payment and settlement systems, said the decision shows that Libra has sparked global competition among central banks to increase the attractiveness of their currencies: "(The six central banks) latest decision is more than just sharing Information, this is also an effort to control Libra … Cryptocurrencies like Libra will make transaction costs lower. The establishment of a joint research group can speed up the pace of large-scale wholesale settlement using central bank blockchain technology. It is still “very high” for central banks to issue digital currencies for small retail settlements because doing so would stifle competition in the private sector. He also dismissed some scholars' view that "the central bank can more easily deepen negative interest rates by issuing digital currencies."