### The Quantum Computing Excitement: Why the Recent “Advancement” in Cryptography Isn’t as Impressive as It Appears
Quantum computing is frequently acclaimed as the next technological frontier, boasting the ability to transform various sectors ranging from pharmaceuticals to AI. Nonetheless, one of the most prominent discussions surrounding quantum computing is its potential to compromise contemporary cryptographic systems that currently safeguard everything from online banking to military communications. Although quantum computers are still in their early stages, the mere prospect of their future capabilities has ignited a surge of sensational headlines and overstated claims about the impending collapse of cryptography.
Recently, yet another instance of this excitement cycle has emerged, with reports from Chinese researchers announcing a “breakthrough” in quantum computing that could endanger military-grade encryption. However, as is often the case with such assertions, the reality is significantly less impactful than the newspapers suggest.
#### The Most Recent “Advancement” in Perspective
Three weeks ago, the *South China Morning Post* conveyed that scientists from Shanghai University had achieved a noteworthy quantum computing advancement. Per the article, the researchers utilized a quantum computer to challenge encryption algorithms based on substitution-permutation networks (SPNs), a framework leveraged in numerous contemporary cryptographic systems. The researchers asserted that this was the first instance of a quantum computer posing a “real and substantial threat” to such encryption techniques.
Nevertheless, the article did not reference the original research paper, and follow-up analyses indicated that the claims were not as revolutionary as initially portrayed. The research paper, published in the *Chinese Journal of Computers*, did not aim to break commonly used encryption algorithms like RSA or AES but rather examined academic block ciphers such as PRESENT, GIFT-64, and RECTANGLE. These lightweight encryption techniques are devised for constrained settings like embedded systems and are not extensively used in critical applications.
#### What the Research Truly Displays
The researchers employed a D-Wave quantum annealer—a kind of quantum computer tailored for resolving specific optimization challenges—to identify integral distinguishers within these SPN-based algorithms. Integral distinguishers are mathematical constructs applied in cryptanalysis to undermine encryption frameworks. However, discovering these distinguishers is nothing new; conventional computing methods have been successful at this task for years.
Fundamentally, the researchers revealed that quantum annealing could parallel the efficacy of traditional mathematical techniques in identifying these distinguishers. While this result is indeed intriguing, it does not signify a breakthrough in breaking widely used encryption methods. As David Jao, an expert in post-quantum cryptography (PQC) at the University of Waterloo, aptly stated: “It’s akin to developing a new technique for lock-picking. The outcome remains unchanged, but the technique is novel.”
#### The Function of Quantum Annealing
Quantum annealing, the approach utilized in this study, is a specialized variety of quantum computing that excels at tackling optimization challenges. It is not synonymous with the more versatile quantum computing that might eventually break encryption algorithms like RSA. D-Wave, the firm behind the quantum annealer employed in this research, has been manufacturing commercial quantum annealers since 2011; however, these systems are restricted in scope and lack the capacity to solve all types of quantum challenges.
The D-Wave Advantage system engaged in the research boasts 5,000 qubits, yet these qubits do not directly equate to those in general-purpose quantum computers. Additionally, the optimization challenges tackled by quantum annealers often need partitioning into smaller sub-challenges, constraining their applicability for extensive cryptographic assaults.
#### The Genuine Menace to Cryptography
Although this latest study does not present an immediate danger to established encryption algorithms, the overarching concern regarding quantum computing’s effect on cryptography remains valid. Once they become fully developed, quantum computers could indeed compromise many of the cryptographic frameworks currently in use. The most susceptible are asymmetric encryption algorithms such as RSA and ECC (Elliptic Curve Cryptography), which depend on the difficulty of factoring large numbers or resolving discrete logarithm problems—tasks that quantum computers could theoretically execute significantly faster than their classical counterparts.
Conversely, symmetric encryption algorithms like AES (Advanced Encryption Standard) are generally deemed secure against quantum threats, as long as key sizes are adequate. For instance, AES-256 is broadly regarded as being resistant to quantum computing assaults.
#### The Significance of Post-Quantum Cryptography
The domain of post-quantum cryptography (PQC) concentrates on crafting new cryptographic algorithms capable of enduring assaults from quantum computers. The U.S. National Institute of Standards and Technology (NIST) has spearheaded an initiative to standardize PQC algorithms, and several candidates are presently under review for widespread implementation.
While quantum computers capable of breaching RSA or AES remain decades in the future, it is vital for industries and governments to commence the transition to quantum-resistant algorithms. The process of substituting existing cryptographic systems is intricate and time-consuming, thus early action is essential to guarantee a seamless transition.
#### Caution Against the Hype
The recent media portrayal of
