Partnership project programme: Quantum

Home   /  The Security And cryptoGrAphic (SAGA) mission

The Security And cryptoGrAphic (SAGA) mission

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The Security And cryptoGrAphic (SAGA) mission is aimed at enabling sovereign, spacebased quantum key distribution (QKD) services for Europe’s governments and critical infrastructure.

Developed in close partnership with the European Commission via the broader European Quantum Communication Infrastructure (EuroQCI) initiative, SAGA is set to form the space segment of Europe’s quantum communication backbone.

In an era of growing digital and cyber threats, Europe’s reliance on secure communication has come under increased scrutiny. SAGA addresses this need by leveraging quantum mechanics to enable cryptographic keys, to shut down any attempt at observation or tampering of sensitive government and institutional data. By enabling secure transmission of encryption keys over long distances, SAGA will contribute to the resilience of Europe’s digital infrastructure.


The importance of SAGA

Digital sovereignty and cybersecurity
SAGA will contribute to European governments and institutions, allowing for access to secure, sovereign communication links, independent of a non-European-controlled infrastructure.
Global reach of QKD
Groundbased fibre networks suffer exponential loss over long distances; by positioning quantum payloads in space, SAGA seeks to overcome terrestrial limitations and enable secure key distribution across continents.
Industrial leadership
By being at the forefront of spacebased quantum communications, SAGA will help Europe maintain and enhance its industrial competitiveness in quantum and optical technologies.


SAGA’s architecture



With a strong industrial ecosystem led by Thales Alenia Space and a clearly defined roadmap, SAGA sits at the intersection of technology, security and European strategic autonomy. As the mission progresses through its design and development phases, it will also serve as a foundation for future quantum networks, potentially enabling a global quantum internet anchored in European space capabilities.


To establish a hybrid cryptographic framework, merging quantum-based key distribution with high-grade classical security, SAGA will feature the following components in its architecture.

Components

Quantum Key Distribution (QKD) payload
The heart of the cryptographic system, this optical payload generates and transmits quantum encryption keys using single photons, ensuring key exchange is inherently secure against eavesdropping due to the laws of quantum mechanics.
Secure Key Management System (KMS)
Manages generation, storage, and distribution of cryptographic keys between the satellite, ground stations, and terrestrial networks, enforcing strict authentication and access control.
Classical Encryption Subsystems
Once quantum keys are exchanged, conventional symmetric encryption is used for data transmission, combining quantum and classical security methods for end-to-end protection.
Trusted Node architecture
Each optical ground station acts as a trusted node, enabling secure key relay between space and terrestrial networks while maintaining cryptographic integrity.
Authentication and integrity verification
Implemented through digital signatures and message authentication codes (MACs) to protect command and telemetry channels.
Tamper-resistant hardware and secure processing units
Embedded in both the satellite and ground infrastructure to prevent unauthorised access, physical tampering, or side-channel attacks.


The phases of SAGA


SAGA’s initial phase has taken place, where it focused on system design and architecture definition, where mission objectives, requirements, and interface control documents are established, outlining how the space and ground segments will interact securely. 


Currently SAGA is under the development and integration phase, where the quantum key distribution (QKD) payload, secure communication modules, and key management systems, as well as the construction and validation of optical ground stations will be created. The verification and validation phase tests end-to-end performance, ensuring the quantum key exchange, encryption mechanisms, and authentication systems meet strict security and operational standards under real-world conditions.


Finally, the deployment and operational phase transitions SAGA into service, where the satellite will perform routine secure key distribution to European ground stations, in support of EuroQCI. The phased approach will ensure that SAGA evolves from a conceptual quantum communication demonstrator to a fully operational system, reinforcing Europe’s strategic autonomy and data security in space-based communications.

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Michael Witting


ESA’s European Space Research and Technology Centre (ESTEC)

Keplerlaan 1

2201 AZ Noordwijk, The Netherlands

+31 625158619

Michael.Witting@esa.int

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Home   /  QKDSat

QKDSat

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Quantum

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In today’s rapidly evolving digital world, the security of communications has become a paramount concern


Traditional encryption schemes face a growing threat from quantum computing, which could render many current cryptographic methods ineffective. In response to this existential challenge, the European Space Agency (ESA) is championing an ambitious project: QKDSat. QKDSat aims to establish a space-based quantum key distribution (QKD) infrastructure that can deliver encryption keys with security guaranteed by the laws of quantum physics.

QKD leverages the properties of individual photons to distribute cryptographic keys between distant parties in such a way that any eavesdropping attempt inevitably disturbs the quantum state and is thereby detected. This capability holds critical importance for securing data across governmental, financial, infrastructure and commercial sectors.

Ground‐based QKD networks are inherently constrained by distance and signal loss, whether in optical fibres or free space. Therefore, satellites offer the only practical route to global-reach QKD, enabling secure key delivery even across continents. The QKDSat initiative is ESA’s contribution to Europe’s digital sovereignty: ensuring access to ultra-secure communications free from external dependency.


QKDSat: an ESA Partnership Project

QKDSat belongs to ESA’s Advanced Research in Telecommunications Systems programme as a Partnership Project with European industry. The lead industrial partner is Honeywell UK, which, in consortium with Redwire Space in Belgium, QTLabs in Austria, as well as companies across Czechia, Switzerland, Canada and the UK, will develop the satellite, payload and ground-segment elements.

The formal contract signature took place on 16 September 2025, marking the transition from concept to delivery phase. This includes not only the satellite platform and payload, but operational demonstrations of QKD key delivery services.


How QKDSat will work 

At its heart, QKDSat uses photon-based quantum links between a satellite and ground stations. The satellite serves as a transmitter of quantum states – for example through single photons, weak coherent pulses – to ground terminals.

The ground terminals decode the states, performing quantum-key extraction, error-correction, and privacy‐amplification to produce a shared secret key. Because any interception would alter the quantum state, the system inherently detects eavesdropping.


Key technical features of QKDSat include:

A satellite-to-ground optical free-space quantum link, enabling secure key delivery over large distances with lower loss than terrestrial fibre.
High-quality random number generation for quantum key material, and integration with classical key-management systems for downstream encryption use.
A scalable service architecture: QKDSat is envisioned not just as a demonstration, but as a pre-commercial system enabling multiple satellites and users (including governmental and telecommunications operators) to access quantum-safe key services.

The impacts of QKDSat

QKDSat’s operational service aims to protect critical infrastructures such as power plants, banking systems, data centres, telecommunications networks and government communications. In effect, QKDSat intends to deliver encryption keys that remain secure even after quantum computers become capable of breaking traditional cryptographic algorithms. 

Beyond the immediate technical gains, the project carries strategic value for Europe by contributing to Europe’s future quantum-communication architecture, stimulating European industry’s competitiveness in the global quantum communications sector and advancing sovereign access to ultra-secure communications beyond reliance on non-European suppliers.

The success of QKDSat is expected to accelerate broader adoption of quantum-secure technologies, contribute to the standardisation of QKD services, and set the foundation for commercial markets in quantum key distribution. The knowledge gained will feed into follow-on ESA Partnership Projects such as EAGLE-1 and the Secure And cryptoGrAphic mission (SAGA), which aim to provide sovereign quantum communications infrastructure for European civil and governmental users.

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CONTACT

Michael Witting

ESA’s European Space Research and Technology Centre (ESTEC)

Keplerlaan 1

2201 AZ Noordwijk, The Netherlands

+31 625158619

Michael.Witting@esa.int

Useful documents

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Home   /  International Use Cases for Operational Quantum Ke...

International Use Cases for Operational Quantum Key Distribution Applications & Services (INT-UQKD)

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In an age where quantum computing looms as a major threat to existing cryptography, the European Space Agency (ESA) has launched a bold project – International Use Cases for Operational Quantum Key Distribution Applications & Services (INT-UQKD) – to pioneer quantum-safe communication infrastructure combining terrestrial fibre and satellite links. 

Funded under ESA’s Advanced Research in Telecommunications Systems (ARTES) programme and via Singapore’s Office for Space Technology & Industry, the project focuses on building operational use cases for QKD: not just lab experiments but real-world demonstrations across global fibre and satellite links. 

Modern communications and data-systems rely heavily on classical cryptography. With quantum computers advancing, many of these cryptographic schemes risk becoming obsolete. INT-UQKD aims to respond to this threat by building a network capable of distributing keys via quantum channels and combining them with post-quantum algorithms to ensure secure communications in the quantum era. 

Beyond the technology, INT-UQKD aims for digital sovereignty, especially for Europe: by developing secure quantum-safe communication systems domestically and internationally, the project helps address the strategic goal of ensuring Europe’s independence and resilience in secure communications. 


Partners of INT-UQKD

Launched in September 2022, INT-UQKD is managed by Starion Luxembourg S.A. as the prime contractor, in consortium with POST Luxembourg, HITEC Luxembourg S.A., the Interdisciplinary Centre for Security, Reliability and Trust (SnT) of the University of Luxembourg, and international collaborators evolutionQ Inc. in Canada and SpeQtral Pte Ltd in Singapore. 

The system architecture is hybrid, and includes:

Terrestrial optical-fibre QKD links between trusted nodes
Satellite QKD links via optical and quantum channels, to reach global distances beyond fibre feasibility.
Integrates post-quantum cryptography to complement QKD – offering a “belt-and-braces” security strategy so that if one layer is broken, the other still holds.


Milestones and key dates

Project start and definition (2022)

  • The project formally commenced on 13 September 2022. 
  • The initial phase focused on definition of use-cases, system requirements, architecture and interfaces, particularly to link terrestrial fibre QKD nodes.


Preliminary design phase (2022–2023)

  • In November 2022, a significant partnership was announced between Starion and SpeQtral to develop a quantum-safe link between Singapore and Europe via satellite, anchored in the INT-UQKD programme. 
  • The project passed its Preliminary Design Review (PDR) in September 2023. 

Terrestrial demonstration phase (2024)

  • The project achieved its first operational terrestrial QKD link between Belgium and Luxembourg (via optical fibre) as part of a use-case demonstration. 
  • InNovember 2024, at ESA’s European Space Security and Education Centre (ESEC) facility in Redu, Belgium, the milestone of the terrestrial link becoming operational was reviewed.


Critical Design Review and space segment preparations (2024 and 2025)

  • The project scheduled its Critical Design Review (CDR) in late 2024 to early 2025 as it prepared to move into the space-link demonstration phase. 
  • Design of the satellite QKD links and optical ground stations was underway (in Luxembourg and Singapore) in preparation for the intercontinental demonstration. 

First satellite launch and global link demonstration (2025 onwards)

  • The first experimental satellite launch took place in November 2025. 
  • An operational satellite follow-up is planned for 2026, for full global link demonstration between Europe and Asia, combining satellite QKD and fibre links. 
  • The resulting hybrid network aims to provide quantum-safe service delivery to institutional users, aligning with larger European quantum communication infrastructures, such as EuroQCI. 

Future expansion and commercialisation (after 2026)

Following the initial demonstrations, the project envisions geographical expansion over European and non-European countries, service maturation and commercialisation of quantum-safe key distribution across critical infrastructure sectors. 

Integration into European initiatives such as EAGLE1 (Europe’s first sovereign LEO quantum-satellite QKD) and the broader EuroQCI initiative, where quantum-communication infrastructures will be pursued, including standards, certification and interoperability. 

RELATED LINKS & CONTACS

CONTACT

Michael Witting


ESA’s European Space Research and Technology Centre (ESTEC)

Keplerlaan 1

2201 AZ Noordwijk, The Netherlands

+31 625158619

Michael.Witting@esa.int

Documents

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Advanced Research in Telecommunications Systems (ARTES)

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Partnership Projects programme

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Home   /  EAGLE-1 

EAGLE-1 

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Quantum

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The EAGLE-1 mission is a flagship endeavour by the European Space Agency (ESA) in collaboration with the European Commission and an industrial consortium of more than 20 European partners led by SES Techcom, to establish Europe’s first space-based quantum key distribution (QKD) system.

Through this mission, the collaboration aims to build a sovereign, ultra-secure communications infrastructure capable of resisting the era of quantum computing and safeguarding sensitive data across national borders.

As quantum-computing technologies progress, traditional cryptographic systems are increasingly vulnerable. QKD exploits the laws of quantum mechanics to distribute encryption keys in a manner where any eavesdropping attempt becomes detectable. By launching EAGLE-1, Europe seeks to pre-emptively guard against future threats and secure the infrastructure of governments, industry and critical services.
EAGLE-1 will be the first space-based quantum key distribution system, significantly boosting European autonomy in cybersecurity and communications.

Additionally, the mission supports strategic aims of digital sovereignty and cross-border resilient connectivity: two pillars of the EU’s upcoming quantum communications infrastructure, EuroQCI.


Mission architecture 

The EAGLE-1 system is an end-to-end quantum key distribution platform comprising a satellite element, optical ground stations, quantum key-management networks and national quantum-communications infrastructures. 

EAGLE-1 will operate from low Earth orbit (LEO) and will distribute quantum keys from space to ground stations, then link into national terrestrial systems. It will test and validate technologies including:

A space-borne quantum key distribution payload, capable of generating and transmitting quantum states to ground.
High-precision optical ground stations equipped with adaptive optics, stable telescopes and fast optical links to receive the quantum signals.
End-to-end key management, integration with national QCI networks, and operational demonstration for governments/critical infrastructure.

EAGLE-1 for sovereign, secure quantum communications

EAGLE-1 is more than a technology demonstrator. It represents a leap in Europe’s ability to build sovereign, secure quantum communications infrastructure.

Quantum-safe communications
Despite advancements in quantum computing, EAGLE-1 ensures key distribution remains secure under future threats.
European industrial leadership
By developing the system within Europe, the mission supports domestic industry, reduces reliance on foreign technology, and enhances competitiveness.
Cross-border connectivity
The satellite enables pan-European secure links across countries and institutions.
Operational readiness
Unlike purely lab-based experiments, EAGLE-1 is designed for real-world applications – particularly governments, telcos, and banks looking to gain early access to satellite QKD capabilities.

The impact of EAGLE-1

Upon successful launch – slated for February 2027 – and in-orbit operation, EAGLE-1 will provide mission data and operational experience to inform future quantum communications systems, with the aim to include:

Deployment of a constellation of QKD satellites across Europe, to provide continuous, worldwide secure key distribution.
Integration of the space-based QKD network with terrestrial fibre QKD links for end-to-end quantum-secure connectivity.
Commercialisation of quantum-safe services for key industries (finance, cloud, defence, critical infrastructure).
Convergence with broader European initiatives such as EuroQCI, incorporating quantum resilience in EU digital infrastructure.

Beyond EAGLE-1: EAGLE-neXt

Proposed in 2025, and building on EAGLE-1, the EAGLE-neXt Partnership Project, will design, develop, qualify, deploy, and validate a satellite-based Quantum Key Distribution (QKD) system – that covers space, control, and user segments – to deliver end-to-end unclassified QKD services to commercial customers and, where appropriate, governmental users.

EAGLE-neXt will evolve the heritage of EAGLE-1 into a fully operational, commercially viable system, maintaining compatibility with EAGLE-1 where feasible. The new system will deliver global unclassified QKD services for security-critical sectors such as finance, telecommunications, and infrastructure, complementing, classified networks such as EuroQCI and SAGA.

EAGLE-neXt will target long-distance and cross-border secure communications not addressable by terrestrial fibre-based QKD networks. Scheduled to begin in early 2026, the EAGLE-neXt project aims to provide the first commercial, space-based QKD service of European origin, building upon EAGLE-1 technology while optimising performance, cost, and scalability.

EAGLE-neXt differs from EAGLE-1 by offering commercial services rather than pure demonstration. It will remain unclassified, focusing on private-sector users. In contrast, SAGA and EuroQCI will provide classified governmental services, operating under the ESA security framework and guided by National Security Authorities. Together, these initiatives form a complementary European QKD ecosystem, balancing public and private capabilities.


Key objectives will include:

Security
Design, development, and operation will follow end-to-end security engineering principles. The system will be resilient to quantum computing attacks and developed to meet forthcoming certification standards.
Performance and cost-effectiveness
Through larger optical apertures, multiple satellites, and improved QKD throughput, the system will lower the cost per cryptographic key and enhance service availability.
Ease of access and integration
Compact, simplified ground terminals will enable easy integration with customer networks and terrestrial QKD systems
Standardisation and interoperability
The system will adopt open standards, ensuring interoperability with European programmes such as the Spanish Caramuel and terrestrial networks.
European technological sovereignty
The project prioritises European industrial participation, particularly for security-sensitive QKD elements.
Certifiability
Working with certification bodies, the project will help define and implement a certification pathway for space-based QKD systems.

RELATED LINKS & CONTACS

CONTACT

Michael Witting


ESA’s European Space Research and Technology Centre (ESTEC)

Keplerlaan 1

2201 AZ Noordwijk, The Netherlands

+31 625158619

Michael.Witting@esa.int

Documents

Overview page

Advanced Research in Telecommunications Systems (ARTES)

Overview page

Partnership Projects programme

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Pioneer

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