Introduction

In a global context in which space has become a strategic arena, the dynamics of space systems, signals, and security require a comprehensive and forward-looking approach. To protect infrastructures from threats, such an approach must integrate technological progress and strategic defense. In this scenario, some countries aim to use cutting-edge technologies, particularly those based on quantum physics, to secure satellite communications. This strategic direction is driven by the recognition that quantum technology (QT) can revolutionize classical paradigms of space strategy. The initiatives seek to create a secure and reliable communication infrastructure, with both space-based and terrestrial components, to ensure the continuity and security of satellite communication services and, in the future, a quantum communication network.

Challenges of Satellite Communications

Satellite communications (satcom) enable the exchange of information between ground terminals via satellites, overcoming line-of-sight limitations. Operating on broader frequency bands, they also allow the high-speed transmission of large volumes of data. Since satellite communications are a critical infrastructure, strong emphasis is placed on their security. Moreover, given the importance of the cyber and space domains in supporting other strategic domains, the interconnection between the two becomes a critical point. However, despite the opportunities they offer, the growth in space systems has increased threats to their security.

Threats to satellite systems mainly manifest through cyber and electronic attacks. Electronic attacks aim to disrupt the signals used for data transmission, while cyber attacks target the data themselves and the systems used for their transmission and management. Electronic attacks include jamming and spoofing techniques. Jamming causes a communication blackout for the duration of the attack due to interference on the radio band linking the satellite and the ground station. Spoofing consists of transmitting falsified signals into the data stream, potentially allowing the attacker to take control of operations until the attack ends.

Cyber attacks can take many forms, including monitoring and intercepting data traffic or injecting corrupted data into a system. The attack surface may include satellites, ground stations, or end-user systems. A cyberattack can lead to the theft, compromise, or manipulation of data, disruption of the communication network, and even control of the satellite, with potentially permanent consequences for the satellite’s operability.

Cyber vulnerabilities not only compromise system performance during an attack but can also undermine trust in cybersecurity principles, influencing perception, strategic calculations, and the attribution of attacks. The difficulty in detecting and preventing cyberattacks highlights the importance of identifying potential vulnerabilities and implementing proactive security measures.

Cyber threats, in addition to targeting communication links, may be directed at space-based or terrestrial infrastructure. Ground stations, which serve as gateways to satellites, often lack adequate authentication measures. Furthermore, the software systems hosted in these facilities require regular updates and patches to address potential threats. Vulnerabilities also extend to the security of supply chain components, the use of commercial satellites for military purposes, the potential presence of cryptographic backdoors, and procedural and personnel-related practices.

The secure exchange of data via satellite communications largely relies on encryption. However, as computing power advances, attackers gain access to increasingly sophisticated tools to break encryption algorithms. Conventional cryptographic techniques are vulnerable to the capabilities of quantum computers, which will soon have the potential to provide highly accurate and exponentially faster solutions to mathematical problems compared to classical computers, making many cryptographic algorithms susceptible to more rapid decryption.

The European Union (EU) recognizes the threats arising from technological progress and has adopted proactive measures to enhance the protection of critical information. The Council Resolution on Encryption of 2020 underscores the importance of a common regulatory framework that facilitates the effective performance of the operational responsibilities of competent authorities and the need to promote quantum encryption. The EU’s 2020 cybersecurity strategy, which anticipates the forthcoming IRIS2 initiative, further explores the interaction between secure satellite communications and cryptography, with a focus on the European Quantum Communication Infrastructure (EuroQCI).

Quantum Technologies Supporting Satellite Communications

The natural characteristics of quantum technology (QT) offer new solutions to address the vulnerabilities of current communication methods. QT exploits the properties of quantum mechanics applied to individual quantum systems, which include particles or quasiparticles such as photons and electrons. Controlling individual systems at the quantum scale represents the goal of the current second quantum revolution.

Quantum technologies have both civilian and military applications and are considered capable of altering the nature of warfare by exponentially enhancing traditional domains. The importance of space capabilities and advances in QT have led to the convergence of these two fields, creating a space-based quantum ecosystem. In this ecosystem, the creation of a secure quantum communication network is not so much about data transfer speed as about the unprecedented level of security offered by protecting data through qubits.

The spectrum of quantum communication applications includes:

• Quantum-Secure Direct Communication (QSDC): enables the transmission of modest volumes of data without the need to distribute keys. It exploits both single photons and entangled photons, reducing vulnerabilities related to cryptographic key storage.
• Position-based quantum cryptography: uses the geographical position of one of the parties as the credential required to access transmitted information. As a result, access is limited to specific locations on Earth.
• Quantum Digital Signature (QDS): comparable to traditional digital signatures, it protects messages from potential intrusions or tampering after they are signed.
• Quantum secure identification: facilitates user identification using quantum attributes and eliminates exposure of authentication credentials.
• Quantum Key Distribution (QKD): ensures robust cryptographic security during the transmission of cryptographic keys and promptly alerts both sender and recipient to any interception attempt. The strength of QKD lies in information-theoretic security, guaranteeing that interception attempts are detected. It is used exclusively for transmitting cryptographic keys, while the actual data are sent through conventional communication channels.

Among these applications, particular emphasis is generally placed on the latter, with the first demonstration carried out by Bennett and Brassard in 1989. To date, the only claims of successful satellite-to-ground QKD come from China, using the Micius quantum satellite. Several countries and organizations are developing QKD networks, including China itself, the EU with EuroQCI (European Quantum Communication Infrastructure), and the United States with the testbed managed by DC-QNet (Washington Metropolitan Quantum Network Research Consortium). The Australian Space Agency plans to deploy a quantum communication network in 2027. The satellite-based QKD market is estimated to grow from a value of half a million dollars in 2025 to over one billion dollars in 2030, with more than 60% of projects driven by national security requirements.

The use of satellites equipped with quantum payloads represents a practical solution for establishing long-distance communication channels. This overcomes the limitations of terrestrial QKD due to environmental noise in the atmosphere, which makes it impractical over distances greater than a few hundred kilometers without the use of quantum repeaters. These repeaters are themselves hindered by topographical features, beyond-line-of-sight transmission issues, physical security considerations, relatively low qubit transmission rates, and high signal losses. In space-based quantum communication, transmission passes through the atmosphere for only about 10 kilometers and partially through empty space, reducing noise and signal loss and thereby increasing overall efficiency and reliability. Given the potential impact of environmental factors and denial-of-service attacks on QKD, an optimal infrastructure should include a constellation of satellites and optical ground stations to enable rerouting of transmission channels.

Challenges in QKD security also lie in the standardization of protocols. In this regard, the International Organization for Standardization (ISO) has developed standards ISO/IEC 23837-1 and ISO/IEC 23837-2.

Conclusions

The creation of a quantum communication infrastructure is essential to ensure the confidentiality of communications and to introduce capabilities for signals intelligence (SIGINT) and communications intelligence (COMINT). Indeed, the transmission of quantum data through individual quanta makes any interception attempt detectable, and the transport of quantum data via coherent photons makes it difficult to locate the communication link without knowing the position of the communicating parties.

However, the development and implementation of such infrastructures require continuous financial support for research, development, experimentation, and collaboration.

If fully realized, a quantum communication infrastructure would become a central pillar guaranteeing the security and resilience of communications, representing both a technological advancement and a strategic asset that places its developers at the forefront of the quantum revolution, satellite communications, and the space and security context.

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Francesco Macci holds an Erasmus Mundus International Master’s Degree in Security, Intelligence and Strategic Studies (IMSISS), a Master’s degree in Leadership for International Relations and Made in Italy, and an advanced training course in Space Institutions and Policies with a scholarship from the Italian Space Agency (ASI). For the Moroccan Institute for Policy Analysis (MIPA), he published “The Growth of the Moroccan Military Air Power” (2023). He coordinated the Security & Defence Working Group of the European Student Think Tank (EST), worked as an intelligence analyst in the private sector, and currently serves as a Security Manager.