With crypto mania sweeping the world, a handful of countries have stirred at the possibility of issuing their own virtual currencies based on blockchain, the technology behind Bitcoin. For now, the idea seems most popular among autocrats looking to evade or undercut international sanctions that are enforced, in part, through the global banking system. But advocates of government-backed cryptocurrencies (so-named because they rely on cryptography for security) say that if the movement takes hold -- which is by no means assured -- it could irrevocably change the international monetary system as we know it.

Russia’s central bank plans to talk to countries including Brazil, China, India and the five former Soviet republics about creating a supra-cryptocurrency that could cover countries with 40 percent of the world’s population. People’s Bank of China Deputy Governor Fan Yifei wrote an article broaching the possibility of a digital currency it would issue with Chinese commercial institutions. In Sweden, where use of cash is vanishing, the central bank is investigating issuing its own digital currency, the E-krona, out of concern that widespread use of other virtual currencies controlled by private actors could harm competitiveness.