Periodic Reporting for period 2 - UNIQORN (Affordable Quantum Communication for Everyone: Revolutionizing the Quantum Ecosystem from Fabrication to Application)
Reporting period: 2020-04-01 to 2022-06-30
The second quantum revolution promises unprecedented advantages in the fields of computing, communication and sensing. The ability to produce, manipulate and detect single quantum states allows for a new kind of information processing based on the laws of quantum mechanics. For computing this means the emergence of quantum computers that can outperform any classical computational task due to exponential speed-up in its processing power. With quantum sensing we have the possibility to build exceedingly precise sensors that work over a wide dynamic range. Communication will especially benefit from quantum enhanced protocols, since the currently employed public key infrastructure is vulnerable to attacks from quantum computers. Our modern way of life is critically dependent on efficient and secure transmission of data. The data traffic increased exponentially in the last decade not only thanks to more people using the internet but also due to the growing business-to-business (B2B) market in database storage and cloud services. So, any vulnerabilities in the security would lead to a loss of confidence in using those services with not only a large impact on businesses but also on our personal lifestyles. Quantum communication is coming to the rescue, because it can provide information-theoretic security against any attacker, even a quantum computer, in the form of quantum key distribution (QKD). However, the technological building blocks are just beginning to emerge from laboratories and further progress is still necessary to make the technology user-friendly and affordable and to incorporate it into our existing communication network infrastructure. The UNIQORN project set out to demonstrate that quantum communication technology can be made into products that offer a benefit to society. On the technology side, the project investigated if photonic integration of key parts of quantum communication systems is possible. This will offer in future the possibility to greatly reduce size and costs of these systems. On the application side the project was trying to show the benefits of QKD and other quantum communication protocols in various use-cases and business scenarios.
On the technology side, the project clearly demonstrated that photonic integration of key parts of quantum communication systems is possible. The project developed a 1 GHz QKD transmitter on chip. After packaging and integrating the chip with a FPGA based pattern generator, a full QKD key exchange cold eb demonstrated. Key generation rates of 800 bit/s per second and distances of up to 30 km were demonstrated. For CV-QKD, the UNIQORN team demonstrated an ultra-low noise amplifier with an electronic noise figure one thousand times smaller than the intrinsic noise of the light field. The amplifier was integrated further with an optical chip featuring a balanced detector assembly. Together they form a low noise receiver unit for coherent quantum communication devices. A hybrid integration method, combining a polymer chip for quantum random number generation with a silicon based single photon detector chip was also successfully demonstrated, paving the way for future lab-on-chip products. To simulate the performance of quantum communication devices, a full toolkit was developed that allows the user to “drag and drop” individual components and assemble them into full systems. The toolkit is capable to simulate components for DV and CV QKD as well as channel noise such as Raman scattering.
On the application side, several use-cases for QKD were identified ranging from securing 5G installations to fiber-to-the-home applications. To showcase the application of quantum communication in data centres, commercial network interface cards (NIC) were adapted to accept random numbers from a quantum random number generator. The integration with standard IPsec headers was demonstrated by implementing a Diffie-Hellman key exchange protocol that shares IPsec authentication and symmetric encryption keys between the two Bluefield NIC endpoints. The project studied a realistic Fiber-To-The-Home (FTTH) network serving up to 32 users. It was based on passive and active telecom equipment which is currently deployed in existing Gigabit Passive Optical Network (GPON)-based infrastructure, installed in the Athens metropolitan area. Three different FTTH scenarios were investigated with varying feeder and distribution lengths (up to a few kilometers). To demonstrate the readiness of QKD for deployment in fiber networks, a QKD key exchange could be demonstrated with classical data channels aggregating a power of 12 dBm using a novel hollow-core fibre type (7.7 km length). This result shows that strong classical data and quantum signals can be distributed simultaneously over the same fiber.
As an example of a non-QKD protocol, the use of quantum one-time programs was investigated, and a suitable use case was developed. This use case is centered around the use of photonic quantum states to represent one-time tokens. The protocol was successfully demonstrated over a deployed fiber with a trusted Token Service Provider distributing quantum states to a client, who measures the tokens in a set of bases that corresponds to a specific merchant ID.
On the application side, several use-cases for QKD were identified ranging from securing 5G installations to fiber-to-the-home applications. To showcase the application of quantum communication in data centres, commercial network interface cards (NIC) were adapted to accept random numbers from a quantum random number generator. The integration with standard IPsec headers was demonstrated by implementing a Diffie-Hellman key exchange protocol that shares IPsec authentication and symmetric encryption keys between the two Bluefield NIC endpoints. The project studied a realistic Fiber-To-The-Home (FTTH) network serving up to 32 users. It was based on passive and active telecom equipment which is currently deployed in existing Gigabit Passive Optical Network (GPON)-based infrastructure, installed in the Athens metropolitan area. Three different FTTH scenarios were investigated with varying feeder and distribution lengths (up to a few kilometers). To demonstrate the readiness of QKD for deployment in fiber networks, a QKD key exchange could be demonstrated with classical data channels aggregating a power of 12 dBm using a novel hollow-core fibre type (7.7 km length). This result shows that strong classical data and quantum signals can be distributed simultaneously over the same fiber.
As an example of a non-QKD protocol, the use of quantum one-time programs was investigated, and a suitable use case was developed. This use case is centered around the use of photonic quantum states to represent one-time tokens. The protocol was successfully demonstrated over a deployed fiber with a trusted Token Service Provider distributing quantum states to a client, who measures the tokens in a set of bases that corresponds to a specific merchant ID.
During the project lifetime, UNIQORN has developed the key components for quantum communication applications such as: photonic integrated quantum random number generation (QRNG) modules, photonic integrated transmitters and receivers for quantum key distribution (QKD), demonstration of an exchange of quantum tokens based on one-time programs, field-deployed dynamic entanglement distribution and fiber-to-the-home QKD networks and a flexible software tool for simulating and designing QKD systems. The project greatly advanced the state of the art on photonic integration be demonstrating QKD transmitters on InP chips, integration of single photon detectors on chip and drastically reducing the size of non-classical photon sources by using a polymer-based substrate to host non-linear crystals for photon generation. Completely novel of quantum communication application such as the quantum token scheme, that was demonstrated by UNIQORN will lead to a greater recognition of the advantages of quantum technologies for a wider user base.
With the outcomes of the project, the next phase of the QT flagship as well as the Euro-QCI initiative can draw valuable lessons and build upon them to realise a European supply chain of components, systems and services within the next years.
With the outcomes of the project, the next phase of the QT flagship as well as the Euro-QCI initiative can draw valuable lessons and build upon them to realise a European supply chain of components, systems and services within the next years.