Chinese researchers have claimed a potential breakthrough in quantum attacks on classical encryption using D-Wave's quantum annealing system. In their study, they propose a method to attack Substitution-Permutation Network (SPN) structured algorithms, which are fundamental to widely-used encryption systems like the Advanced Encryption Standard (AES). This work represents the first time a real quantum computer has been shown to pose a significant threat to full-scale SPN algorithms such as Present, Rectangle, and Gift-64 block ciphers. The researchers argue that their method could be extended to attack other public-key and symmetric cryptographic systems, sparking renewed debate on the future of encryption security in the quantum era.

Although the specifics of the quantum attack method remain unclear, the paper adds urgency to concerns that quantum computing will eventually break classical encryption. Some experts predict that quantum computers capable of breaking encryption might be decades away, while others, like Singapore's central bank, warn it could happen within the next ten years. Vendors are already introducing "quantum-safe" encryption methods, but fears persist that current data may be stolen and decrypted once quantum computers become more advanced.

Technical Key Points:

• Quantum Annealing Attack: The researchers used D-Wave's quantum annealing system to target SPN-based encryption algorithms like AES, Present, Rectangle, and Gift-64.
• SPN Vulnerability: These block ciphers are vulnerable to quantum-based optimization techniques that can exploit their structure to break encryption.
• Scalable Threat: The approach could potentially be applied to other cryptographic systems, including both public-key and symmetric encryption.
• Real and Substantial Threat: This is the first instance where a quantum computer posed a significant threat to full-scale algorithms widely used today.
• Quantum Decryption Timeline: Opinions vary on when quantum computers will be powerful enough to break encryption, with estimates ranging from 10 to 30 years.
• Stealing Now, Decrypting Later: There are concerns that nations like China might steal encrypted data now to decrypt it later when quantum capabilities advance.

The research highlights the critical need to accelerate the development of post-quantum cryptography. While we may still have years or decades before quantum computers can routinely break classical encryption, the threat is becoming real. Organisations should begin preparing by:

• Monitoring Quantum Developments: Stay informed about advancements in quantum computing, particularly those related to cryptography.
• Adopting Quantum-Safe Algorithms: Transition to quantum-resistant cryptographic methods as soon as they become feasible to mitigate future risks.
• Data Lifecycle Management: Evaluate the sensitivity and longevity of encrypted data. Sensitive information with a long lifecycle (e.g., defence contracts) may need to be protected with stronger, future-proof encryption now to prevent decryption later.
• Collaboration and Research: Engage with ongoing research in quantum cryptography and collaborate with industry leaders to stay ahead of the curve.

The future of cryptography stands on the brink of a quantum revolution, and what was once unbreakable may soon crumble. For governments and companies, this represents not just a technological shift, but a race against time—a battle to secure the very foundations of national security, financial systems, and private data before the quantum dawn breaks. Those who fail to adapt risk leaving their most sensitive secrets vulnerable to the unstoppable force of quantum decryption, where today’s encrypted assets could be tomorrow’s open books. The future isn't waiting, and neither should we.

Source and further reading.

Tong, Z., & Tong, Z. (2024, October 11). Chinese scientists hack military grade encryption on quantum computer: paper. South China Morning Post. https://www.scmp.com/news/china/science/article/3282051/chinese-scientists-hack-military-grade-encryption-quantum-computer-paper

Dobberstein, L. (2024, October 14). Crypto-apocalypse soon? Chinese researchers find a potential quantum attack on classical encryption. The Register. https://www.theregister.com/AMP/2024/10/14/china_quantum_attack