Possible projects in quantum computing
Possible projects in quantum computing
Project goal
We present here a number of interesting projects in quantum computing that we have discussed with different partners, but for which there is still no formal collaboration. The objective is to attract interest from the user community and create a critical mass that could allow us to establish collaborations with users and vendors.
Collaborators
Project background
OpenQKD: Testbed for quantum key distribution
OpenQKD is a European Horizon 2020 project to test quantum key distribution (QKD) technology and to prepare a panEuropean QKD deployment to protect European citizens and economies against the potential security threat posed by a quantum computer. The threeyear project started in September 2019. With a budget of €18 million, 38 European partners are developing fibrebased and freespace QKD and deploying over 30 use cases at 16 sites across Europe. Among these, several use cases are planned in Geneva. One of them is the socalled Quantum Vault, which aims to protect digital assets against failures and attacks. As a proof of concept, the Quantum Vault is being realised in six Genevan data centres and telecom nodes. CERN openlab and the Poznan Supercomputing and Networking Center in Poland are supporing the Quantum Vault by hosting one node at the CERN Data Centre. It is planned to actively involve CERN openlab by running a proper use case taking advantage of the Quantum Vault infrastructure.
Quantum generative adversarial networks
Generative adversarial networks (GANs) are among the most interesting models in classical machine learning. GANs are an example of generative models, i.e. models that learn a hidden distribution from the training data set, and can sample new synthetic data. At CERN openlab, we have been investigating their use as an alternative to Monte Carlo simulation, obtaining remarkable results. Much faster than standard Monte Carlo algorithms, GANs can generate realistic synthetic data, while retaining a high level of accuracy (see our fast simulation project). Quantum GANs could have more representational power than classical GANs, making them better able to learn more complex distributions from smaller training data sets. We are now training a quantum GAN to generate images of a few pixels and we are investigating two possible approaches: a hybrid schema with a quantum generator learning the target PDF, using either a classical network or a vibrational quantum circuit as a discriminator (variational quantum generator), as well as a full quantum adversarial implementation (quGAN).
Track seeding optimisation
The Kalman filter is widely used in highenergy physics for track fitting of particle trajectories. It runs after an initial patternrecognition step where detector ‘hits’ are clustered into subsets belonging to the same particle. Currently, several patternrecognition approaches exist. Quantum computing can be used to reduce the initial combinatorial search using the ‘quantum approximate optimisation algorithm’ developed by researchers at the Massachusetts Institute of Technology (MIT) in Cambridge, US. We are now studying the application of what is known as the ‘variationalquantumeigensolver algorithm’ and implementing it on Intel’s quantum simulator.
Quantum homomorphic encryption
The latest advances in machine learning and data analytics offer great potential for gaining new insights from medical data. However, data privacy is of paramount concern. Anonymisation via the removal of personal information is not an option, since medical records carry information that may allow the identification of the owner much more easily and securely than the name or the birth date. One possibility being studied is to encrypt sensitive information in such a way that makes data analytics possible without decryption. This is called homomorphic encryption. It is important to find an encryption strategy that is secure, while also ensuring it is possible to apply a large family of analytic algorithms to the data. While such encryption algorithms do exist, they require highquality random numbers and they tend to be very demanding in terms of computing resources. Thus, this is a promising field of investigation for the utilisation of quantum computing.
The aims of the project are multiple: to transfer anonymised medical records protected by Quantum Keys, to develop a quantum homomorphic encryption (QHE) algorithm to apply on it and to analyse the data with QHEfriendly analysis tools (techniques based on machine learning or deep learning). The main project consists of four different parts, each realised in collaboration with different partners, both European and Korean: ID Quantique, Innosuisse (the Swiss Innovation Agency), Korea Institute of Science and Technology Information (KISTI), and the Seoul National University Bundang Hospital (SNUBH).
Quantum random number generator
We have recently established a collaboration with Cambridge Quantum Computing to test the performance of a new quantum randomnumber generators and study its integration within simulation software used in highenergy physics.
RandomPower: evaluating the impact of a lowcost, robust ‘true random power generator’
Researchers at the University of Insubria in Italy have invented a true random power generator (TRNG). This is based on the local analysis of the time series of endogenous selfamplified pulses in a specific silicon device. The principle has been validated with lab equipment and a lowcost, smallformfactor board has been developed and commissioned with the support of an ATTRACT project. The board can deliver a stream of unpredictable bits at frequencies currently up to 1Mbps for a single generator, with the possibility to be scaled up. Randomness has been qualified through a test suite from the US National Institute of Standards and Technology, as well as beyond this. Together with the CERN openlab, the University of Insubria intends to evaluate the impact of the TRNG availability in a set of use cases, as follows:
 Modifying the Linux OS, replacing the embedded random number generation with the random power stream, in order to facilitate its adoption.
 Comparing the outcome of the application of generative adversarial networks using training sets guided by pseudo random number generators (PRNG) or the random power TRNG.
 Identifying classes of Monte Carlo simulations in highenergy physics where the use of PRNG could be particularly critical.
Moreover, the availability of a lowcost platform for highquality random numbers may open up new possibilities in the use of homomorphic encryption, relevant for privacypreserving data analysis; this will be thoroughly evaluated.
Recent progress

Next steps
Publications
 E. F. Combarro, F. Carminati, S. Vallecorsa, et al., On protocols for increasing the uniformity of random bits generated with noisy quantum computers. Published in J Supercomput, 2021. cern.ch/go/9DGk
 M. FernándezPendás, E. F. Combarro, S. Vallecorsa, J. Ranilla, I. F. Rúa, A study of the performance of classical minimizers in the Quantum Approximate Optimization Algorithm. Published in Journal of Computational and Applied Mathematics, 2021. cern.ch/go/6mVk