by David Maroto Carmona (ERNI Spain)
In the previous article, we explored the fundamental concepts behind quantum computing. However, the more important question is a strategic one: what will quantum computing actually be used for? The answer lies in the identification of problems where quantum principles can provide a competitive advantage. Cryptography, healthcare, artificial intelligence, advanced materials and secure communications are among the fields where companies, governments and research institutions are already investing heavily. This second article focuses on these aspects: the use cases that make the most sense today, the developments that could shape the future, and the conditions that must be met for this technology to deliver real value.
Cryptography and security: The transition has already started
One of the most widely discussed use cases for quantum computing concerns an area with a direct impact on our daily lives: information security.
If large-scale, fault-tolerant quantum computers become a reality, quantum algorithms such as Shor’s algorithm could threaten widely used encryption systems, including RSA and parts of elliptic curve cryptography. These technologies currently protect online communications, banking transactions, digital certificates, medical records, critical infrastructure and much of the security underpinning the internet.
The main threat can be summarised in a simple phrase: “harvest now, decrypt later.” An attacker could intercept and store encrypted information today, with the intention of decrypting it in the future once sufficiently powerful quantum computers become available. This is particularly relevant for sectors where data must remain confidential for many years, including banking, defence, healthcare, public administration, intellectual property and manufacturing.
The organisations most exposed to this risk have already begun preparing through several key initiatives. The first is cryptographic inventory management: understanding which algorithms are in use, where they are deployed, which systems depend on them and what data they protect.
The second is the transition to post-quantum cryptography. This does not involve using quantum computers for encryption. Instead, it means adopting classical cryptographic algorithms specifically designed to resist known quantum attacks. In 2024, the National Institute of Standards and Technology (NIST) published its first set of finalised post-quantum cryptography standards, providing a clear signal that the transition is already under way.
The third is the adoption of cryptographic agility: designing architectures that can replace algorithms, certificates and protocols without requiring an entire platform to be rebuilt. This will be essential because the transition will not happen all at once. For many years, legacy systems, hybrid approaches and new standards will need to coexist.
Source: QNB
The business impact is clear: reducing risk before it becomes urgent. Quantum computing has not yet broken modern cryptography at a practical scale, but it is already reshaping cybersecurity roadmaps. Around the world, private organisations and governments are making substantial investments in quantum technologies, with global annual spending on quantum computing in 2026 estimated at around 80 billion euros, according to QBN.
One of the fields where quantum computing could have the greatest business impact is medicine, particularly in drug discovery and molecular design.
Developing a new medicine is a lengthy, expensive process with a high degree of uncertainty. Before reaching clinical trials, pharmaceutical companies must identify candidate molecules, study how they interact with proteins or enzymes, assess their stability, estimate their toxicity, and eliminate thousands of options that are unlikely to prove viable.
Much of this work depends on understanding chemical phenomena that occur at the quantum level, including molecular bonds, electron distributions, energy states, and interactions between molecules. This is where quantum computers could provide significant value by reducing the number of hypotheses that need to be tested experimentally.
A simple analogy is designing a key for a biological lock. The protein represents the lock, while the candidate molecule is the key. Today, researchers test millions of possible keys using approximate models, laboratory screening, and experiments. A sufficiently mature quantum system could help determine more precisely the shape, energy, and behaviour that the key should have before it is manufactured or physically tested. The expected outcome would be more efficient R&D, better early-stage decisions, and lower costs associated with pursuing unproductive research paths.
Artificial intelligence: Practical applications in quantum computing
The relationship between quantum computing and artificial intelligence is genuine, but it is often overstated by assuming that combining the two will automatically result in more advanced or even conscious AI.
Research in quantum machine learning is exploring how quantum algorithms can be applied to machine learning problems. However, there is still no proven general advantage over the models that currently dominate applied AI.
One promising application is using AI to calibrate quantum devices, reduce decoherence and optimise their control systems. Another is applying quantum computing to specific simulation or sampling tasks whose outputs can then be used by AI systems.
The most realistic vision is not that of „a chatbot running inside a quantum computer“, but rather hybrid architectures in which each technology is responsible for the tasks it is best suited to perform.
For businesses, the focus should be on high-value applications such as scientific modelling, complex simulations, analysing vast solution spaces, or processes where even modest improvements in accuracy or speed could deliver significant economic benefits.
Future prospects: Majorana 1
Few recent announcements have attracted as much attention as Majorana 1, the quantum chip unveiled by Microsoft in 2025. (Source: Microsoft’s Majorana 1 chip carves new path for quantum computing) The company introduced it as a processor based on topological qubits and linked it to a scalable architecture capable of supporting up to one million qubits on a single chip. Such computing power could reduce the time required to solve certain highly complex problems from billions of years using today’s methods to potentially just a matter of days.
The great promise of this approach is that quantum information can be better protected against decoherence, one of the biggest challenges facing quantum computing.
Imagine trying to store information by drawing a line in the sand. Any small disturbance, such as the wind or someone walking past, can easily erase it. This is how today’s qubits behave: they are extremely sensitive to their surroundings. Now compare that with tying a knot in a rope. The rope can move or bend, but as long as the knot remains, the information is preserved. Topological qubits aim to achieve something similar by storing information in the system’s overall structure rather than in a fragile local state. This makes them more stable because small disturbances are not enough to alter that state.
Majorana 1 could mark a turning point. Equally, it may prove to be just one promising step on a much longer journey. In either case, it reflects the current state of quantum computing: significant progress, high expectations, and growing interest as the technology continues to mature.
Quantum repeaters: The future of the quantum internet
When quantum computing is discussed, most of the attention focuses on the processor. In communications, however, another component is just as crucial: quantum repeaters.
Their role is not to amplify a signal, as in conventional telecommunications, but to extend quantum entanglement over long distances without copying quantum information, something that cannot be done in a conventional network.
Their practical importance lies in the fact that, without them, long-distance quantum communication is limited by signal loss and noise. As this technology matures, it could enable new possibilities for secure key distribution, advanced synchronisation, and network services that currently have no direct equivalent in the classical internet.
The so-called quantum internet should not be imagined as a faster version of today’s internet. Instead, it would be a fundamentally different infrastructure designed to connect quantum devices, share entanglement, and enable entirely new forms of communication and security.
Profitability: Energy, cost and real competitive advantage
One of the most important questions for any business is whether this technology will be commercially viable.
A quantum computer today is far more than a single chip. It is a complete system that requires cryogenics, sophisticated electronic controls, shielding, continuous calibration, error correction, and operation at temperatures close to absolute zero. This makes the underlying infrastructure highly complex and expensive.
As a result, quantum computing will not automatically be more efficient or less costly than classical computing. Its economic value will depend on a practical comparison: how much energy, infrastructure, and investment it requires versus the value of the problem it can solve.
In many cases, a conventional supercomputer will remain the best option. However, for highly specific problems, a quantum system could justify its cost if it significantly reduces computation times, improves the quality of decision-making, eliminates the need for unnecessary physical testing or enables the analysis of scenarios that were previously beyond reach.
If it helps develop a new medicine, protect critical data, discover an advanced material or simulate a system that cannot currently be modelled accurately, its energy consumption and infrastructure costs may be outweighed by the economic or strategic value it creates.
Conclusion: A new tool for new frontiers
The future of quantum computing is unlikely to be one of widespread replacement, but rather coexistence.
Classical computers will continue to underpin almost all everyday computing. Specialised accelerators will remain the dominant technology for industrial AI. And quantum processors, if they fulfil their promise, will be reserved for high-value applications in cryptography, medicine, materials science, advanced artificial intelligence and quantum networking.
For businesses, the challenge will be to avoid adopting quantum computing simply because it is the latest technological trend, and instead to identify where it can deliver genuine value. In this context, ERNI’s role is to help organisations prepare for that future, from assessing the impact on cybersecurity and supporting the transition to post-quantum cryptography, to exploring realistic use cases where quantum computing can be integrated into existing systems.
Preparing today does not mean adopting the technology before its time. It means being ready to take advantage of it when it reaches the level of maturity needed to deliver meaningful economic, scientific or strategic impact.
