Quantum supremacy: what it is, how it works and impact on technology, security and geopolitics

March 16, 2026

Quantum supremacy is the point at which a quantum computer can solve a task that is practically infeasible for classical systems to complete within a reasonable timeframe. Beyond performance alone, this milestone signals a paradigm shift with implications for today’s computing, Cybersecurity, cryptography, geopolitics, and the development of new technological capabilities.

In other words, it is reached when a quantum system demonstrates computational capabilities beyond the reach of the most advanced classical supercomputers, even if the specific task it solves does not yet have a direct practical application.

This breakthrough not only redefines the limits of computing, but also anticipates profound transformations across strategic sectors and in the protection of information.

It is important to bear in mind that:

Quantum computers rely on qubits, which can represent both 0 and 1 at the same time through the principle of superposition, and can form entangled states that enable massively parallel information processing.
Classical computers operate with bits that can only take a single value (0 or 1) at any given time, limiting computation to sequential models or much more constrained forms of parallelism.

—A quantum computer is considered to have achieved quantum supremacy when it applies these principles to solve a problem with an exponential computational advantage over classical systems.

Quantum supremacy is not only about power, but about redefining what is possible.

Implications and challenges of quantum supremacy

In 2019, NASA and Google conducted a demonstration in which Google’s Sycamore quantum processor achieved what is known as quantum supremacy. This processor completed a specific sampling task in approximately 200 seconds. A timeframe that, according to estimates, would have required around 10,000 years using the world’s fastest classical supercomputer. Improved classical simulations later reduced that gap, shifting the focus toward quantum advantage and quantum utility in practical workloads.

In this context, researchers at the University of Texas at Austin have provided a mathematical demonstration of quantum supremacy. Meanwhile, D-Wave has experimentally demonstrated this phenomenon. As a result, the independent mathematical proof provides definitive support for these findings.

This supremacy does not mean that quantum computers are now universally superior. It only shows that, for at least one specific problem, quantum computing outperforms classical methods.

The next step is to achieve quantum advantage, meaning that quantum computers solve useful real world problems better or faster than classical ones.

Quantum supremacy opens new scientific and technological horizons.

Technological transformation and challenges in the quantum era

Achieving supremacy represents a discontinuity in computational capability, with cascading effects on materials discovery, drug design, energy optimization, logistics, and finance.

It also reshapes geopolitical power through control of talent, intellectual property, standards, and quantum supply chains, while accelerating Cybersecurity and post quantum privacy risks that make it necessary to address a rapid cryptographic transition.

It is important to note that supremacy drives the creation of new markets related to hardware, control systems, compilers, and specialized algorithms, fostering the concentration of intellectual property in areas such as error correction and software platforms.

Nations are moving toward strengthening their technological sovereignty by establishing leadership in standards, implementing subsidies, developing robust supply chains, and shaping cloud access policies aimed at reducing lock in risks and addressing talent shortages. These efforts are further supported by technology diplomacy.

To ensure that quantum supremacy demonstrations translate into practical benefits, more qubits are required, along with lower error rates, improved connectivity, and large scale error correction, which implies significant overhead per logical qubit. Domain specific advantages may emerge first, but a cryptographically relevant quantum computer (CRQC) capable of breaking RSA 2048 will likely require millions of high fidelity physical qubits and is still years away.

ENISA published, through the European Union Cybersecurity Certification (EUCC), the Cryptographic Guidelines, stating that:

“RSA keys larger than 1900 bits but smaller than 3000 bits (for example, 2048 bits) are officially classified as deprecated, with their use permitted until December 31, 2025. They also highlight the possibility of establishing a later acceptability deadline at national level for user and data authentication with this specific algorithm.”

This leads to their obsolescence and invalidity in the context of qualified signatures and seals (QSCD), as organizations are now in the process of planning their transition to the cryptographic guidelines established by ENISA and the EUCC.

Quantum supremacy does not mark the end of classical computing, but the beginning of a new computational paradigm.

RSA obsolescence and the need for cryptographic transition

It should be noted that the CCN recommends that responsible organizations proceed with the implementation of more robust mechanisms for asymmetric keys, such as RSA with greater key lengths and post quantum algorithms, as soon as possible. For this reason, coordination, collaboration, and cooperation among stakeholders, both nationally and internationally, are essential to establish standards for cryptographic transitions, ensure transparency of capabilities, and apply responsible export controls.

Practical approaches include aligning standards consortia (EU, NIST, ETSI, ISO), creating a shared register of quantum risks, incident reporting and benchmarking, and adopting do not decrypt first policies to foster trust in sensitive cross border data.

Finally, quantum supremacy does not mark the end of classical computing, but the beginning of a new computational paradigm. It demonstrates that quantum computers can outperform the most advanced classical systems in specific tasks, transforming our understanding of complexity, security, and technological limits. However, the real challenge now lies in turning this milestone into sustainable, reliable, and scalable applications that deliver real world impact.

Quantum progress is driving the acceleration of the transition toward more secure cryptographic algorithms, marking the beginning of a new era in digital protection.