From Cyberspace to the Quantum Realm

For over three decades, cybersecurity has been one of the invisible yet crucial pillars of the international order. While remaining in the background of public debate, it has underpinned the stability of global finance, the confidentiality of diplomatic communications, the reliability of supply chains, and the security of digital military architectures.

This equilibrium was founded on a fundamental assumption: the breach of cryptographic systems, while theoretically possible, required a timeframe incompatible with the strategic value of the protected information.

Today, this assumption is being challenged not by a single vulnerability, nor by a sudden attack, but by a more profound transformation: the emergence of the quantum paradigm. Quantum computing, far from being a mere incremental evolution of digital technologies, introduces a methodological discontinuity destined to affect the very nature of information, the ways in which it is processed, and the conditions under which it is protected.

In this context, cybersecurity ceases to be a matter confined to the technical sphere and emerges as a central component of contemporary geopolitical and geoeconomic competition.

The shift from the “non-quantum” paradigm to the “quantum” one, in fact, does not merely entail a redefinition of security tools but affects the very structure of trust upon which the global digital order rests.

In this sense, quantum technology does not merely herald a new phase of technological innovation: it heralds a reconfiguration of power relations within the international system.

Security as a Function of Time

The architecture of modern cybersecurity is based on a fundamental principle: certain mathematical problems are computationally intractable for classical digital systems. Cryptographic schemes such as RSA (Rivest–Shamir–Adleman) and ECC (Elliptic Curve Cryptography) derive their strength from the difficulty of factoring large numbers or solving problems on elliptic curves within time frames compatible with the strategic utility of the protected information.

This leads to a crucial consequence, one that is often implicit but decisive: security is not an absolute property, but rather a function of time. A system can be considered secure not because it is theoretically unbreakable, but because the time required to compromise it exceeds the operational, political, or economic value of the data it protects. In this sense, modern cryptography has ensured not so much unbreakability as the effective management of the duration of secrecy.

This balance, however, is profoundly altered by the emergence of the quantum paradigm. Algorithms such as Shor’s demonstrate, at least in theory, that problems considered unsolvable by classical computers can be solved in significantly less time. Although these capabilities are not yet fully operational on an industrial scale, their plausibility is already sufficient to alter the behavior of strategic actors, introducing anticipatory and long-term-oriented approaches.

In this context, a particularly significant trend is emerging, known as “harvest now, decrypt later”: the ability to intercept and store encrypted information today in order to decrypt it in the future, when quantum capabilities make it possible. Security thus ceases to be a condition tied to the present and becomes a variable projected into the future.

This leads to a profound conceptual shift: security no longer concerns only the immediate protection of information, but its persistence over time. In other words, what is at stake is no longer merely the secrecy of data, but the enduring nature of the trust upon which political, economic, and strategic relationships are founded.

Quantum Computing as a Systemic Enabling Technology

Quantum computing should be viewed not as a sector-specific technology, but rather as a systemic enabling technology, comparable in impact to nuclear energy or the Internet. Unlike these, however, quantum computing does not merely enhance existing capabilities, but directly impacts the structure of trust that underpins the digital order.

In the classical digital paradigm, security is probabilistic but relatively stable: the possibility of a breach exists, but it remains confined within predictable and manageable limits. The system, though imperfect, maintains its consistency over time. In the quantum paradigm, security is not simply strengthened or weakened, but redefined: during the transition phase, it becomes a temporar , potentially reversible, since what is protected today may not be tomorrow, and what appears secure may retroactively prove vulnerable. This introduces a deeper form of uncertainty, no longer tied to the immediate probability of a breach, but to its potential realization over time.

In this context, pre-quantum information protection can no longer be conceived as a stable state, but as a dynamic process, based on continuous adaptation and the management of vulnerability over time. From a strategic standpoint, this implies that quantum computing does not simply represent a new computational tool, but a true vector of power. Actors equipped with advanced quantum capabilities not only strengthen the protection of their own systems but also gain the ability to access others’ systems undetectably, profoundly altering information asymmetries.

In this sense, quantum computing does not merely redistribute technological capabilities; it redefines the very conditions of strategic superiority within the international system.

The Geopolitics of Quantum Computing: The Race for Control Over Trust

The geopolitical dimension of quantum technology is now clear. The major global powers have launched strategic programs to develop quantum technologies, recognizing their value not only in the technological sphere, but also in the military, economic, and political spheres. In this sense, quantum technology is already emerging as a new arena of competition for the definition of the balance of power.

The United States is focusing on a highly integrated ecosystem spanning the private sector, research, and defense, in which technological innovation is combined with the ability to set global standards. NIST’s role in standardizing post-quantum cryptography is a prime example of this strategy: controlling standards ultimately means influencing global security architectures.

China, by contrast, takes a systemic and centralized approach, characterized by massive public investment and close integration between the state apparatus, the technology sector, and strategic planning. Rather than competing on existing standards, Beijing aims to build a self-sufficient technology ecosystem capable of reducing dependence on Western infrastructure and models.

With its 2025 Quantum Europe Strategy, the European Union has recognized the strategic importance of the sector, promoting research, infrastructure, and training. However, the main challenge lies not in defining the vision, but in the ability to translate it into industrial and operational scale. Without this leap forward, there is a risk of incomplete technological sovereignty, vulnerable to the competitive dynamics among major global players.

In this context, quantum technology is not merely a field of innovation, but a battleground for control over global digital trust. It is not simply a matter of developing new technologies, but of determining who will be able to protect—or compromise—the information infrastructures of the future. In other words, quantum technology not only redefines capabilities, but also helps to reshape the hierarchy of power within the international system.

Implications for security and alliances

The implications of quantum computing for international security are particularly significant in the context of alliances.

If today’s encrypted communications can be decrypted in the future, the entire system of intelligence sharing and military planning risks being compromised retroactively.

This introduces a new form of vulnerability: one that is not immediate or visible, but rather delayed over time and potentially systemic.

This dynamic directly affects trust among allies, transforming it from an implicit assumption into an uncertain strategic variable. Within NATO, for example, communications security is one of the pillars of deterrence and operational cohesion.

The possibility that such communications could be decrypted after the fact profoundly alters strategic calculations, as it introduces the risk that shared decisions, plans, and assessments could be reconstructed and exploited at a later time.

This results in a significant shift: vulnerability no longer concerns only the protection of data in the present, but its exposure over time. In this context, deterrence also undergoes a transformation, as the credibility of shared commitments and capabilities can be eroded retroactively.

In this sense, quantum technology represents not only a technological challenge but a matter of collective security and the stability of the international system.

It introduces a structural tension within alliances, in th e that it calls into question one of their fundamental premises: trust in the confidentiality and durability of shared information.

Quantum Geoeconomics and Supply Chain Control

The geoeconomic dimension of quantum technology is equally significant. Control over quantum technologies extends beyond the development of individual devices; it entails mastery of a complex supply chain that includes advanced semiconductors, photonics, innovative materials, software, and communications infrastructure.

In this context, quantum technology is part of the broader competition for control over technological value chains. Those who control these supply chains not only gain an industrial advantage but also set operational standards, guide innovation, and, above all, determine security conditions. In other words, control of the supply chain translates into control over the architectures of digital trust.

The geoeconomic dimension thus takes on strategic importance: it is not merely a matter of producing technologies, but of determining who will be able to set the rules of the game in the digital sphere. In this sense, quantum computing represents a central issue in the competition for technological sovereignty.

For countries like Italy, the challenge lies not simply in participating in this dynamic, but in defining their own position within it. The shift from a logic of participation to one of strategic integration requires the coordinated development of expertise, infrastructure, and industrial capabilities, as well as a clear role within the European and global supply chain. Without making this leap, there is a risk of structural dependence on technologies and standards developed elsewhere.

The shift from the classical digital paradigm to the quantum one marks a profound transformation of cybersecurity and, more broadly, of the international order. Cybersecurity, once a predominantly technical function, is emerging as a central component of contemporary geopolitical competition.

In this new context, security can no longer be conceived as a stable state, but as a dynamic process of adaptation. There is no longer any definitive protection, but rather a continuous management of uncertainty. Consequently, power will not be determined solely by the ability to protect information, but by the ability to manage its vulnerability over time.

Quantum technology does not merely introduce new technological capabilities: it alters the very conditions of trust upon which the global digital order is founded. Whereas in the previous paradigm security guaranteed an imperfect but predictable stability, in the quantum paradigm it becomes inherently temporary and potentially reversible.

Ultimately, quantum technology is not merely a new phase of technological innovation, but the point at which trust. the cornerstone of political, economic,  and strategic relations becomes the primary arena of competition in our century.

This article was first published in Italian by European Affairs on March 22, 2026 and is republished with permission of the author.