Chinese scientists use quantum computers to crack military-grade encryption — quantum attack poses a "real and substantial threat" to RSA and AES

Chinese researchers claim to have uncovered a “real and substantial threat” to the classical cryptography widely used in banking and the military sectors. According to a report published by the SCMP, the researchers utilized a D-Wave quantum computer to mount the first successful quantum attack on widely used cryptographic algorithms. These algorithms, classed as substitution–permutation network (SPN) cryptographic algorithms, are at the heart of widely used standards like the Rivest-Shamir-Adleman (RSA) and Advanced Encryption Standard (AES).

The Chinese-language research paper is titled Quantum Annealing Public Key Cryptographic Attack Algorithm Based on D-Wave Advantage (PDF). The paper outlines how two technical approaches grounded in the quantum annealing algorithm can be used to challenge classical RSA cryptographic security.

The first attack route is “entirely based on D-Wave computers,” explains the paper. It coaxes the Canadian quantum computer into a cryptographic attack by presenting the combination of an optimization problem and exponential space search problem to the computer. The issues are solved using the Ising and QUBO models.

The second proposed attack incorporates classical computing-based cryptographic technology, such as the Schnorr signature algorithm and the Babai rounding technique, layered with a quantum annealing algorithm, to work “beyond the reach of traditional computing methods.”Applying the above techniques, with the help of the D-Wave quantum computer, the team led by Wang Chao of Shanghai University claim to have successfully breached the widely used SPN structure. Wang refused to give further details to the SCMP due to the sensitivity of this topic. However, the direction of travel means that AES-256 and other ‘military grade’ encryption algorithms are closer than ever before to being cracked. Moreover, quantum-reliant and quantum-aided techniques, as discussed in the paper, quantum-reliant and quantum-aided techniques could bring forward the day when current military and enterprise-grade encryption tech is good enough.

With the above news in mind, it is reassuring that organizations like the National Institute of Standards and Technology (NIST) are busy assessing and establishing post-quantum cryptographic algorithms designed to be crack-proof to future quantum computers.