As per present time many world leaders are thinking to Regulate crypto currencies as on world wide bases and also talking for realesed own country's own Crypto currencies but How can regulated it as on worldwide base 
Easy, for the international world to do crypto or world-based digital currency, have you read about: Central bank digital currency, more precisely under the name CBDC digital currency, this is the plan of the current world leader in implementing world-based crypto.You need to see more about: Which Countries Have CBDCs?
This is how the world does it.
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The present concept of "central bank digital currency" may have been partially inspired by Bitcoin and similar blockchain-based cryptocurrencies. It is also a known concept in the field of economics, whereby the central bank enables citizens to hold accounts with it, providing a reliable and safe public savings or payments medium ("retail" or "general-purpose" CBDC).