Spanish industry aims to position itself in the QKD League of quantum keys
Just after the 68th anniversary of the launch of Earth's first artificial satellite, Sputnik-1, by the now defunct Soviet Union, the Spanish space industry is determined to play in the first division of the extraterrestrial QKD league.
It is an invisible shield that aims to prevent quantum computers, which are expected to become a reality in the 2030s, from deciphering any secret encrypted message, even with the most sophisticated algorithms.
Technology analysts are confident that quantum computers will achieve full supremacy in the next 5 to 10 years and that, from then on, the intelligence agencies and official institutions of the nations that possess them, but also hackers and criminal organisations, ‘will be able, in less than an hour, to break the impregnable asymmetric keys currently used by governments, financial institutions and large companies,’ says Ángel Álvaro, technical director of the QKD project at Thales Alenia Space Spain.
The activation of the national QKD initiative is part of the European Recovery Funds through the Ministry of Science's PERTE Aerospace programme and is funded by the Centre for Technological Development and Innovation (CDTI). Designed to ‘shield’ data communications and secret information, its raison d'être is to anticipate the imminent arrival of quantum computing, while strengthening the European Union's secure communications infrastructure.
Two consortia of Spanish companies are working flat out on two projects for the distribution of quantum keys or QKD, which stands for Quantum Key Distribution. The two are very different, but they have the same objective: to develop quantum encryption systems via satellite to create a barrier that will curb cyber attacks and cyber espionage on communications between two high-level political, military, economic or financial interlocutors.
A new era of secure communications begins
On the one hand, there is the consortium led by Sener Aeroespacial, which is working to bring a LEO QKD demonstrator to fruition, to be operated from low Earth orbit or LEO. Funded with €18 million, the Spanish company is seeking ‘an in-orbit demonstration opportunity’ to carry out technological tests of its quantum key, says its general manager of Space, Diego Rodríguez, which will be carried out on board a communications satellite positioned between 500 and 700 kilometres above the Earth.
In contrast, the industrial group led by Thales Alenia Space Spain is committed to developing a GEO QKD prototype that will operate from geostationary orbit, or GEO. If it becomes a reality, it would be the first quantum key distribution system installed on board a device positioned no less than 36,000 kilometres from Earth, covering almost a third of the Earth. The initiative is extremely complex, which is why it is being financed with £103.5 million.
What is QKD? It is a disruptive technology that ‘opens a new era for secure communications,’ summarises Ismael López, CEO of Thales Alenia Space Spain. It involves ‘distributing encrypted keys to two parties who want to communicate with maximum confidentiality, so that only they have the ability to decrypt and read the messages they exchange. No one else!’
For Ángel Álvaro, head of the team developing GEO QKD, ‘it is essential to be prepared well in advance.’ He argues that when powerful quantum computers become operational, ‘the first to use them for nefarious purposes will be able to penetrate, break and dive into any current encryption method, no matter how sophisticated.’ ‘From that moment on,’ Ángel Álvaro continues, ‘all data and reports classified as secret will be compromised.’
The great advantage offered by QKD, whether LEO or GEO, is that, due to the physical and mathematical principles of quantum mechanics, ‘keys created with quantum algorithms can only be read once.’ Consequently, if someone tries to copy, spy on or steal the key, ‘such action automatically and immediately alters and paralyses the key transmission sequence.’ The result is that ‘any intrusion attempt is instantly exposed, without allowing any access to the information, even partially,’ explains Ángel Álvaro.
Both QKDs aim to protect critical infrastructure against cyber espionage aimed at disrupting the operation of large power plants, water management systems, hospitals and, of course, the transactions and secrets jealously guarded by states, the armed forces, banks and financial institutions, for example.
Millions of photons for the benefit of national security
The goal is to establish transmissions that are almost impossible for third parties to decrypt and resistant to attacks by powerful quantum computers by hackers, criminal organisations or third countries seeking to appropriate critical data or information linked to national security.
The full development of quantum computers is just around the corner, and their first users will be able to decrypt current encryption systems, including RSA, the most widely used form of asymmetric cryptography in the world. The RSA key system is an acronym for the surnames of its creators, American professor Ron Rivest, Israeli Adi Shamir and fellow American Leonard Adleman, who developed it at the Massachusetts Institute of Technology in 1977 and whose algorithms, in practice, allow for total confidentiality... until now.
Thales Alenia Space Spain's GEO QKD technology will undergo ground testing before being tested in space. This will take place in the first half of 2026, between the islands of La Palma and Tenerife, some 150 kilometres apart. After the necessary adjustments, its flight component will be shipped on a Hispasat communications satellite, which will fire photons at a ground receiving station to generate random encryption keys, which will be immediately forwarded to the interested parties. It should be remembered that, in essence, photons are subatomic particles that carry all forms of electromagnetic radiation.
As project manager at Thales Alenia Space Spain, Ángel Álvaro explains that the space component of GEO QKD carries as its main instrument a ‘pulsed laser, super fast and very weak’, whose function is to fire 500 million photons per second, i.e. "500 mega pulses that are very short and of low intensity. But he emphasises that ‘of all the photons, around 10,000 will reach Earth’. And what happens to the rest? ‘Well, they are absorbed by the atmosphere, so we have created an accounting algorithm to identify which photons reach their destination and which do not’.
The project led by Thales Alenia Space Spain is undoubtedly the most complex in terms of development and the most difficult to carry out. To find out how it is progressing, the Secretary General for Innovation, Teresa Riesgo, visited the company's headquarters in Tres Cantos, near Madrid, a few days ago, together with the Secretary General for Telecommunications, Matías González Martín, and the Director General of the CDTI, José Moisés Martín.
The development of the GEO QKD demonstrator is the result of the technologies of the group of companies and institutions led by Thales Alenia Space Spain, a company owned 67 per cent by Thales France and 33 per cent by the Italian corporation Leonardo. It is made up of Arquimea, GMV, Hispasat, IDOM, Indra, the Canary Islands Astrophysics Institute, Qdynamics, Quside, Tecnobit, Thales Cybersecurity, the Universities of Vigo and Madrid Polytechnic, and the National Crytotological Centre.
The LEO QKD, led by Sener Aeroespacial, involves the participation of Deimos, Hisdesat, Hispasat, Indra, Luxquanta, Quside, the Canary Islands Astrophysics Institute, the Institute of Photonic Sciences and the Institute of Space Studies of Catalonia.