The rise of cryptocurrency such as Bitcoin, based on blockchain, in the second half of the 2010s threatened the seigniorage power of governments around the world. Its private promoters dangle privacy to convince people to use the cryptocurrency in transactions and usurping the role of traditional fiat money issued by governments. At the cryptocurrency frenzy peak in April 2021, there were more than 6000 cryptocurrencies and stable coins in the market with a value of over $2 trillion.