Physics vs. Code: Why Google’s ‘Quantum Money’ Could Make Blockchain Obsolete

Google Quantum AI researchers, with collaborators at the University of Texas at Austin and the Czech Academy of Sciences, have revived a decades-old theoretical concept called quantum money, in which currency is secured by the no-cloning theorem rather than by a blockchain. Dar Gilboa, a Google Quantum AI researcher and co-author of the study "Anonymous Quantum Tokens with Classical Verification," said the work is theoretical and not a Bitcoin replacement. He said the system relies on a trusted central issuer such as a bank, so it is not decentralized, and it requires a large fault-tolerant quantum computer and quantum communication that remain far beyond current capabilities.