InQKD (Integrated Quantum Key Distribution) is an 18-month research project led by Alter Technology TUV Nord UK Ltd, in collaboration with Covesion Ltd and the Institute of Photonics at Leibniz University Hannover. Commencing in November 2024 and funded by Innovate UK with a grant of £390,000, the project aims to accelerate the commercial viability of quantum-secure communication technologies by delivering a scalable entangled photon source for frequency-bin quantum key distribution (QKD).
With the aim of developing a compact, robust, and cost-effective quantum light source that will play a critical role in enabling ultra-secure communications, the InQKD project is particularly focused towards low SWAP-C (size, weight, power and cost) applications, with plug-and-play compatibility with existing telecom infrastructure.
Quantum key distribution represents a paradigm shift in data security. Unlike traditional encryption methods, QKD is inherently resistant to cyber-attacks, even those launched by future quantum computers, thanks to the fundamental properties of quantum mechanics. By using entangled photons to distribute encryption keys, QKD systems can detect any attempt at eavesdropping, ensuring complete data confidentiality.
Applications for QKD span sectors where data security is paramount, including finance, healthcare, defence, autonomous transport systems, and national infrastructure. However, the widespread adoption of QKD has been hindered by the lack of reliable, compact sources of entangled photons that can be manufactured at scale and integrated into existing networks.
The InQKD project addresses this challenge directly.
The innovation at the heart of InQKD is the use of spontaneous parametric down-conversion (SPDC) using a Covesion waveguide to generate entangled photon pairs at 1550 nm, an optimal wavelength for fibre-based communication networks. This method converts incoming laser light at 775 nm into entangled pairs, using custom non-linear optical components engineered for high efficiency and stability.
The InQKD project brings together a manufacturing-oriented consortium capable of delivering a product ready for market adoption. Alter Technology UK leads the initiative and will drive the product through to commercialisation. Covesion contributes critical component expertise in non-linear crystals, while Leibniz University Hannover provides deep research expertise in integrated quantum optics. Together, the partners aim to create a disruptive, low-cost entangled photon source with direct market relevance. By prioritising manufacturability and modular integration, InQKD will offer a rugged, fibre-coupled, frequency-bin entanglement source that can be deployed in telecommunications, secure data centres, and national security infrastructure.
Further commercialisation opportunities arising from the InQKD project include delivering a functional testbed for frequency-bin QKD systems, enabling practical validation and demonstration. In addition, it will produce custom non-linear SPDC components and rugged, deployable QKD modules designed for real-world use. The project will also establish hybrid photonic packaging processes that are essential to supporting the next generation of photonic devices across a range of industrial applications.
With quantum computers on the horizon, the urgency to secure communication infrastructure has never been greater. The National Institute of Standards and Technology (NIST) has already begun defining post-quantum cryptographic standards, and global governments are investing heavily in quantum resilience. The InQKD project aligns with this momentum, advancing hardware-based quantum security solutions. It supports the UK’s strategic vision to be a global leader in quantum technologies, creating new IP, supply chain capabilities, and exportable products. By addressing both the technological and commercial challenges of scaling QKD, InQKD represents a significant step forward in the realisation of practical quantum-secure networks.
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