For over a decade, the world of digital currencies has been built on a single foundation: blockchain.
This complex code-based distributed ledger system was an innovative approach to creating digital scarcity and preventing counterfeiting.
But now researchers at Google are exploring a concept that could avoid that entirely: securing funding through basic physics rather than code chains.
This new research on “quantum money” provides an alternative to cryptocurrencies like Bitcoin and targets the very problems blockchain was designed to solve.
If successful, it would effectively eliminate the need for blockchain’s core technology, a big assumption since it presupposes advanced quantum computers, and would present a fundamentally different path towards a secure digital future.
In a new study, ”Anonymous quantum token with classical verification,” Researchers at Google Quantum AI, the University of Texas at Austin, and the Czech Academy of Sciences have advanced the decades-old idea of a theoretical currency protected by the invariant laws of quantum mechanics.
This paper outlines a system in which money is not just data on a ledger, but a unique quantum object whose integrity is guaranteed by the very fabric of reality.
uncopyable dollar
This concept is based on one of the strangest and most powerful principles in physics: the No-Copying Theorem.
This law states that it is impossible to create a perfect, independent copy of an unknown quantum state. A set of data on a computer can be copied infinitely, but a quantum state cannot.
“If you had a $1 bill that was actually in a quantum state, you could prove based on the properties of quantum mechanics that it would be impossible to copy such a state,” said Dar Gilboa, a Google quantum AI researcher and co-author of the study. decryption. “There is only a very low chance of success.”
In this system, counterfeiting is not just computationally difficult, as it is with Bitcoin. It is physically prohibited.
Replace the ledger with physics
This is where this technology poses a direct threat to the blockchain model.
The main function of blockchain is to prevent “double spending” without a central authority. This is accomplished by creating a large-scale, public, and immutable set of accounting books that everyone can monitor, a distributed ledger.
Quantum money solves the same problem much more directly. If tokens exist, a global ledger is not required to track ownership history. itself It cannot be physically copied and can only be used once.
- Blockchain stores transaction history on a ledger.
- Quantum money ensures safety the token itself.
If each digital dollar had inherent physical security, the entire energy-intensive apparatus of a proof-of-work blockchain would be redundant. Verification is a direct physical process, not a global consensus event.
Different philosophies: a centralized compromise
Quantum money could replace blockchain technology, but it does not share its decentralized philosophy. Gilboa was quick to make this distinction.
“We are not solving the same problems,” he stressed. “What we are doing is not decentralized, so it is not an analogue of cryptocurrencies in any strong sense.”
The Google model assumes that a trusted central issuer, such as a bank, creates quantum tokens. But it makes great use of physics to keep this issue honest.
The system is designed to provide strong privacy guarantees and prevent banks from tracking proprietary currencies. Users can team up to “swap test” their quantum tokens.
“If they’re not the same, that means the bank may be tracking you,” Gilboa said. Any attempt by the bank to covertly tag the funds will be immediately apparent.
A glimpse of the distant future
This financial revolution won’t happen tomorrow.
Gilboa emphasizes that this research is entirely theoretical and far beyond current capabilities.
“This presupposes not only having a large, fault-tolerant quantum computer, but also the ability to do quantum communications…which is a very different and very difficult engineering challenge,” he says.
Still, research is very important.
This shows that blockchain, the defining technology solution of the past decade, is not the only solution to securing digital value. The brute force accounting of distributed ledgers could one day be replaced by the elegant absolute laws of the quantum realm.
“This is a crazy tool,” Gilboa concluded. “You can do all these wild things. It’s high risk, high reward, but that’s what’s exciting about it.”
