Chinese quantum breakthrough could potentially challenge AES-256 encryption

Chinese researchers have taken a step forward in using quantum computing for cryptographic analysis, though the impact isn’t as dramatic as initially reported. Led by Wang Chao from Shanghai University, a team has explored a fresh approach to analyzing certain encryption algorithms with quantum annealing.

Their findings, shared in the Chinese Journal of Computers, center on identifying integral distinguishers in specific lightweight block ciphers that use substitution-permutation network (SPN) structures. The team applied their technique to three academic cipher models: PRESENT, GIFT-64, and RECTANGLE.

What they’ve developed is a new method they call Quantum Annealing-Classical Mixed Cryptanalysis (QuCMC), which:

• Blends quantum annealing with classic mathematical tools
• Utilizes a D-Wave Advantage quantum computer with 5,000 qubits
• Matches—but doesn’t surpass—the capabilities of current classical computing approaches

While this is a fantastic new approach, it’s worth noting that it doesn’t create any new risks for mainstream encryption methods like AES or RSA. The findings just mirror what classical computers achieved back in 2018.

So, while this is progress in exploring quantum computing for cryptography, it’s not a leap that puts our current encryption at risk. Algorithms like AES-256, for instance, are still considered secure against quantum attacks if set up correctly.

In the bigger picture, this research adds to what we know about post-quantum cryptography but also reminds us that we’re still a long way from having quantum computers that could crack today’s encryption standards. As a point of reference, experts think breaking a 2048-bit RSA key would take a quantum computer with around 20 million qubits—far beyond the 1,000-qubit milestone reached last year.