Chinese scientists ‘create’ quantum code-breaking algorithm, US experts worried

Hong Kong, Jan 11

A Chinese team has claimed that their new, quantum code-breaking algorithm could dramatically reduce the scale of a practical quantum computer, which has raised eyebrows in the US, media reports said on Wednesday.

The team, led by Professor Long Guilu of Tsinghua University, claimed in a paper (yet to be published) that its new algorithm could reduce the scale of a practical quantum computer to 372 qubits - even less than that of IBM's Osprey, reports South China Morning Post.

Osprey operates with "433 qubits and is nowhere near breaking codes".

IBM in November last year unveiled a new 433 qubit Quantum processor that has the potential to run complex quantum computations well beyond the computational capability of any typical computer.

Called 'IBM Osprey,' it has the largest qubit count of any IBM quantum processor, more than tripling the 127 qubits on the IBM 'Eagle' processor unveiled in 2021.

According to the report, the new claim by Chinese scientists has left senior security and quantum experts in the US concerned.

American cryptographer Bruce Schneier said the Chinese claim "is something to take seriously".

"It might not be correct, but it's not obviously wrong. And there's the nagging question of why the Chinese government didn't classify this research," Schneier said in a blog post.

Scott Aaronson, director of the quantum information centre at the University of Texas at Austin, said a major problem with the Chinese research paper "was its failure to clarify the advantage of quantum technology over classical computers".

"It seems to me that a miracle would be required for the approach here to yield any benefit at all, compared to just running the classical Schnorr's algorithm on your laptop," Aaronson wrote in a blog post.

According to IBM, the number of classical bits that would be necessary to represent a state on the 'IBM Osprey' processor far exceeds the total number of atoms in the known universe.

"The new 433 qubit 'Osprey' processor brings us a step closer to the point where quantum computers will be used to tackle previously unsolvable problems," said Dr Dario Gil, Senior Vice President, IBM and Director of Research.

--IANS