Quantum computers won’t be a threat to cryptographic systems for much longer, according to Fujitsu

A study published by Fujitsu confirms that quantum computers do not represent, and will not represent for some time, a threat to current cryptographic systems. However, there is no rest on our laurels, because the development of these devices is proceeding quickly.

Even Fujitsu confirms: quantum computers are not yet a danger

Last summer the NIST, the US body that sets cryptographic standards, has published the first four algorithms designed to resist attacks by quantum computers. The prediction is that such devices will be powerful enough to break current public key-based algorithms in about a decade.

A study by Fujitsu goes in this direction: using a version of Shor’s algorithm, Fujitsu researchers have calculated how much an error-resistant quantum computer would need to 10,000 qubits and 2.23 trillion quantum gates to break RSA, and it would take 104 days of uninterrupted and error-free calculations. For comparison, the most qubit quantum processor currently available is the IBM Osprey, with 433 qubits but far from error-resistant.

The estimate was made using a quantum simulator developed by Fujitsu itself and run on the Fugaku supercomputer: “Using a cluster based on Fujitsu’s PRIMEHPC FX700 supercomputer hardware, which is equipped with the A64FX CPU, and a new technology that automatically and efficiently rearranges quantum bit state information, Fujitsu achieved a speed increase of more than 100 times over a 64-knot system with no rearrangement, and was able to factor N=253 in 463 seconds, versus the previous result of 16 hours.”

Chinese researchers claimed they were able to crack RSA2048 with just 372 qubits last month, but that position appears controversial. There is indeed little agreement within the cryptographic and quantum community as to when quantum computers will actually reach the point where they will be a threat to current cryptographic systems. Many seem to agree that it will still take a long time, but this is still not a good excuse not to act now and implement post-quantum systems.

“Our research shows that quantum computers pose no immediate threat to current cryptographic systems. We still can’t take things lightly, though. The world needs to start preparing now for the possibility that quantum computers could one day transform radically the way we think about security”he has declared Tetsuya Izu, senior director of data and security research at Fujitsu.