People

Elham Kashefi
Group Leader

Quantum Cryptography, Hardware Security, Quantum Internet Protocols, Quantum Cloud Computing, Verification of Quantum Technology, Experimental Implementation of Quantum Protocols, Foundation of Quantum Mechanics, Quantum Parallel Computing, New Models for Quantum Computing, Quantum Simulation and Learning

Harold Ollivier
Research Associate

Quantum error correcting codes, quantum cryptography and quantum networks.

Theodoros Kapourniotis
Research Associate

Security, Delegated Computing, Verification

Mahshid Delavar
Research Associate

Cryptography, post-quantum cryptography, protocol zoo, hardware security.

Niraj Kumar
Research Associate

Quantum machine learning, benchmarking and verification of quantum computation, secure communications.

Rawad Mezher
Research Associate

Quantum randomness / Quantum Supremacy / Verification of near-term quantum devices

Sima Bahrani
Research Associate

Benchmarking, Quantum Networks, Quantum Protocol Zoo

Mina Doosti
PhD student

Cryptography, post-quantum cryptography, protocol zoo, hardware security.

Ellen Derbyshire
PhD student

Randomized benchmarking, certification, quantum simulation, analogue quantum simulation, scalable testing, approximate t-designs

Pierre-Emmanuel Emeriau
PhD student

Foundation, nonlocality and contextuality

Yao Ma
PhD student
Dominik Leichtle
PhD student

Quantum Cryptography, Post-Quantum Cryptography, Delegated Blind Quantum Computing, Verification of Quantum Computing, Provable Security

Alexandru Cojocaru
PhD student

Quantum Cryptography, Post-Quantum Cryptography, Delegated Blind Quantum Computing, Verification of Quantum Computing, Provable Security

Léo Colisson
PhD student

Quantum Cryptography, Post-Quantum Cryptography, Delegated Blind Quantum Computing, Verification of Quantum Computing, Provable Security

Brian Coyle
PhD student

Quantum machine learning, quantum advantage, testing, variational algorithms, device independent cryptography

Daniel Mills

Quantum Computational Supremacy, Verification, Benchmarking, NISQ Technology, Classical Simulation of Quantum Systems, Quantum Computing Software

Paul Hermouet
PhD student

Quantum advantage, Cryptography, Protocol Zoo, device independent cryptography

Luka Music
PhD student

Quantum cryptography, secure multiparty quantum computing.

Armando Angrisani
PhD student

Quantum machine learning, quantum advantage, privacy-preserving machine learning, generative models, statistical learning theory

Constantin Dalyac
PhD student

Quantum Simulation, Verification and benchmarking

Artin Tajdini
Intern

Verification and Benchmarking

Former Members
  • Ieva Cepaite (Master and Project Student)
  • Flaviu Cipcigarn (Project student)
  • Julien Du Crest (Project student)
  • Raphael Dias (Visiting Ph.D. student)
  • Leonardo Disilvestro (Master and project student)
  • Tom Douce (Postdoc)
  • Vedran Dunjko (Postdoc and Ph.D. student)
  • Patric Fulop (Project student)
  • Alexandru Gheorghiu (Postodc, PhD and Master student)
  • Matty Hoban (Postdoc)
  • Borislav Ikonomov (Master student)
  • Marc Kaplan (Postdoc)
  • Theodoros Kapourniotis (Postdoc, Ph.D. and Master student)
  • Pia Kullik (Project student)
  • Shane Mansfield (Postdoc)
  • Martin Marinov (Project student)
  • Anna Pappa (Postdoc)
  • Einar Pius (Ph.D. and Master studnet)
  • Shraddha Singh (Master Student)
  • Phivos Sofokleous (Project student)
  • Iskren Vankov (Project student)
  • Petros Wallden (Postdoc)
photo Elham

Elham Kashefi



Keywords:
Quantum Cryptography, Hardware Security, Quantum Internet Protocols, Quantum Cloud Computing, Verification of Quantum , Experimental Implementation of Quantum Protocols, Foundation of Quantum Mechanics, Quantum Parallel Computing, New Models for Quantum Computing, Quantum Simulation and Learning

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DETAILS
photo Harold

Harold Ollivier



Keywords:
Quantum error correcting codes, quantum cryptography and quantum networks.

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My interests span from foundations of quantum theory to quantum error correction and cryptography.
I currently focus on projects related to the advent of a quantum internet such as: what protocols could be useful to run on such networks, how to improve them to take into account realistic noisy devices, and how to benchmark and asses the quality of networks.
photo Ulysse

Ulysse Chabaud



Keywords:
Quantum certification / Continuous variable quantum information theory / Quantum optics / Quantum cryptography

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Quantum certification:
How do we check the correct functioning of the quantum device? Answering this question is a timely problem in the absence of fault-tolerant mechanisms, for benchmarking existing and upcoming quantum technologies.
The task of certification may vary depending on the context: fundamental research, industrial quantum device, or even delegated quantum computing and quantum cryptography. In all these cases, what may vary is the level of trust one wants to guarantee, as well as the assumptions one is ready to make.
Our contribution is a variety of protocols and techniques covering all these contexts, and using tools from quantum cryptography to guarantee security for the user.

Articles:
– Building trust for continuous variable quantum states, Ulysse Chabaud, Tom Douce, Frédéric Grosshans, Elham Kashefi, Damian Markham, arXiv preprint arXiv:1905.12700 (2019)
– Quantum certification and benchmarking, Jens Eisert, Dominik Hangleiter, Nathan Walk, Ingo Roth, Damian Markham, Rhea Parekh, Ulysse Chabaud, and Elham Kashefi, arXiv preprint arXiv:1910.06343 (2019, Review paper)

Continuous variable quantum information theory:
A great part of the theory already developed for discrete variable quantum information is still missing for continuous variable quantum information. The latter gives different perspectives on quantum information. In addition, continuous variable quantum information has an exciting experimental status, thanks to quantum optics in particular, which enables the scalable generation of large entangled quantum states and provides high efficiency measurements.
Our work covers a variety of subjects: quantum computational supremacy in continuous variable, certification of continuous variable quantum states, theory of non-Gaussian states.

Articles:
– Continuous-variable sampling from photon-added or photon-subtracted squeezed states, Ulysse Chabaud, Tom Douce, Damian Markham, Peter Van Loock, Elham Kashefi, and Giulia Ferrini, Physical Review A, Vol 96 no 6, 062307 (2017)
– Building trust for continuous variable quantum states, Ulysse Chabaud, Tom Douce, Frédéric Grosshans, Elham Kashefi, and Damian Markham, arXiv preprint arXiv:1905.12700 (2019)
– Stellar Representation of Non-Gaussian Quantum States, Ulysse Chabaud, Damian Markham, and Frédéric Grosshans, Physical Review Letters, Vol 124 no 6, 063605 (2020)

Quantum optics:
Quantum optics provides an exciting experimental platform for existing, near-term, and long-term quantum applications. Quantum states of light allow for many possible encodings, with applications ranging from quantum communication, quantum computing and quantum cryptography.
We develop protocols and applications that can be readily implemented using quantum optics.

Articles:
– Optimal quantum-programmable projective measurement with linear optics, Ulysse Chabaud, Eleni Diamanti, Damian Markham, Elham Kashefi, and Antoine Joux, Physical Review A, Vol 98 no 6, 062318 (2018)
– Quantum information processing with coherent states: optimal and programmable toolkit schemes, Niraj Kumar, Ulysse Chabaud, Elham Kashefi, Damian Markham, and Eleni Diamanti, in preparation (2020)
– Quantum weak coin flipping with a single photon, Mathieu Bozzio, Ulysse Chabaud, Iordanis Kerenidis, Eleni Diamanti, in preparation (2020)

Quantum cryptography:
Properties of quantum information such as entanglement and no-cloning allow for cryptographic applications such as quantum key distribution, blind quantum computing, etc. At the same time, adversarial parties also have access to quantum powers, meaning that the security of existing and upcoming protocols have to be proven against quantum adversaries.
With this concern in mind, our work covers a broad range of cryptographic protocols for various applications.

Articles:
– Building trust for continuous variable quantum states, Ulysse Chabaud, Tom Douce, Frédéric Grosshans, Elham Kashefi, Damian Markham, arXiv preprint arXiv:1905.12700 (2019)
– Quantum weak coin flipping with a single photon, Mathieu Bozzio, Ulysse Chabaud, Iordanis Kerenidis, Eleni Diamanti, in preparation (2020)
– Security of Quantum Position Verification BB84-like protocols, Andrea Olivo, Ulysse Chabaud, André Chailloux, and Frédéric Grosshans, in preparation (2020)
photo Theodoros

Theodoros Kapourniotis



Keywords:
Security, Delegated Computing, Verification

For more details click here
It looks increasingly likely that in the future a few universal quantum computers will be available worldwide and remote users will require access to these. We study the setting where a set of clients with very basic quantum technology want to delegate their computations to a set of universal quantum servers. Each client wants their input, computation and output kept secret from the server and the other clients. Our goal is to resolve the outstanding question of the minimal security assumptions, hardware or software, that enable security in this setting. Also, how these assumptions are made relevant in a realistic quantum network setting. Finally, we also investigate the role of verification in the same setting.

Related papers:
Gheorghiu, Alexandru, Theodoros Kapourniotis, and Elham Kashefi. “Verification of quantum computation: An overview of existing approaches.” Theory of computing systems 63.4 (2019): 715-808.
Mills, Daniel, Anna Pappa, Theodoros Kapourniotis, and Elham Kashefi. “Information theoretically secure hypothesis test for temporally unstructured quantum computation.” QPL/IQSA (2017).
Kashefi, Elham, and Anna Pappa. “Multiparty delegated quantum computing.” Cryptography 1.2 (2017): 12.
Kapourniotis, Theodoros, Vedran Dunjko, and Elham Kashefi. ”On optimising quantum communication in verifiable quantum computing”, Proceedings of the 15th Asian Quantum Information Science Conference (2015)
Dunjko, Vedran, Theodoros Kapourniotis, and Elham Kashefi. “Quantum-enhanced secure delegated classical computing.” Quantum Information & Computation 16.1-2 (2016): 61-86.
Kapourniotis, Theodoros, Elham Kashefi, and Animesh Datta. “Blindness and verification of quantum computation with one pure qubit.” 9th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2014). Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik, 2014.
photo Mashid

Mahshid Delavar



Keywords:
Cryptography, post-quantum cryptography, protocol zoo, hardware security.

For more details click here
Hardware Security:
Like other areas of the security field, quantum technology might have advantages or disadvantages in the field of hardware security. There are several proposals on the design of universal composable cryptographic protocols based on hardware assumptions in classical settings. The question that we are addressing is whether quantum technology threatens the security of hardware assumptions introduced so far or boosts their security by using the features of quantum mechanics. Currently, we are working on Physical Unclonable Functions (PUFs), One-Time Memory (OTM) and Hardware Enclave as cryptographic hardware primitives. The results of our work are found in the following links:
Quantum Physical Unclonable Functions: Possibilities and Impossibilities: https://arxiv.org/pdf/1910.02126.pdf
In this work, we formally define the notion of quantum PUFs (qPUFs) and their security considering different attack scenarios and computational capacity of the attackers. We show the vulnerability of qPUFs against an unbounded quantum adversary as well as quantum polynomial-time (QPT) adversaries where the target of the attack is generating a valid quantum challenge-response pair of the qPUF. On the other hand, we prove qPUFs are secure against QPT adversaries who aim to estimate the correct response to an unknown quantum challenge chosen by another party. Our security proof shows qPUFs provide the required security notion to be used in cryptographic protocols even in the quantum world.

Cryptography and Post-quantum cryptography:
Shor’s algorithm showed the vulnerability of widely-deployed cryptographic algorithms and protocols to the emergence of quantum technology. This initiated wide research on exploring other quantum adversarial algorithms and attack scenarios as well as finding countermeasures to improve the security of cryptographic primitives, algorithms and protocols against quantum adversaries. Our research includes developing quantum adversarial algorithms, proposing quantum secure constructions for known cryptographic primitives and design of quantum-secure cryptographic protocols.
photo Mina

Mina Doosti



Keywords:
Cryptography, post-quantum cryptography, protocol zoo, hardware security.

For more details click here
Hardware Security:
Like other areas of the security field, quantum technology might have advantages or disadvantages in the field of hardware security. There are several proposals on the design of universal composable cryptographic protocols based on hardware assumptions in classical settings. The question that we are addressing is whether quantum technology threatens the security of hardware assumptions introduced so far or boosts their security by using the features of quantum mechanics. Currently, we are working on Physical Unclonable Functions (PUFs), One-Time Memory (OTM) and Hardware Enclave as cryptographic hardware primitives. The results of our work are found in the following links:
Quantum Physical Unclonable Functions: Possibilities and Impossibilities: https://arxiv.org/pdf/1910.02126.pdf
In this work, we formally define the notion of quantum PUFs (qPUFs) and their security considering different attack scenarios and computational capacity of the attackers. We show the vulnerability of qPUFs against an unbounded quantum adversary as well as quantum polynomial-time (QPT) adversaries where the target of the attack is generating a valid quantum challenge-response pair of the qPUF. On the other hand, we prove qPUFs are secure against QPT adversaries who aim to estimate the correct response to an unknown quantum challenge chosen by another party. Our security proof shows qPUFs provide the required security notion to be used in cryptographic protocols even in the quantum world.

Cryptography and Post-quantum cryptography:
Shor’s algorithm showed the vulnerability of widely-deployed cryptographic algorithms and protocols to the emergence of quantum technology. This initiated wide research on exploring other quantum adversarial algorithms and attack scenarios as well as finding countermeasures to improve the security of cryptographic primitives, algorithms and protocols against quantum adversaries. Our research includes developing quantum adversarial algorithms, proposing quantum secure constructions for known cryptographic primitives and design of quantum-secure cryptographic protocols.
photo Ellen

Ellen Derbyshire



Keywords:
Randomized benchmarking, certification, quantum simulation, analogue quantum simulation, scalable testing, approximate t-designs

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My research centres on usability/performance of near term quantum devices, and currently quantum simulators used primarily for emulating physical phenomenon. Up to now, this has taken the form of finding efficiently scalable methods of noise characterisation/performance testing of analogue quantum simulators, which follow continuous time dynamics. I have worked on adapting randomized benchmarking (a well known scalable method for testing average performance of quantum devices) to the analog setting, as well as designing a framework for generating approximate t-designs in this setting. These designs lead to many applications such as the aforementioned benchmarking, as well as quantum cryptography, security, demonstrating a quantum computational advantage, etc. Additionally, I am interested in general in how noise affects different circuits and whether benchmarking can be used to provide a stronger characterisation of noise than ‘average’ in analog and other quantum simulators. I am broadly interested in applications of current quantum devices, and characterising their performance for specific and general use.

Publications:
Randomized Benchmarking in the Analogue Setting – E. Derbyshire, J. Y. Malo, A. Daley, E. Kashefi, P. Wallden, arXiv: 1909.01295, currently under review for Quantum Science and Technology, IOP Journal.
photo PE

Pierre-Emmanuel Emeriau



Keywords:
Foundation, nonlocality and contextuality

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I am broadly interested in identifying and understanding quantum advantages over classical computation – specifically related to nonlocality and contextuality – arising in quantum systems. I have been focused on developing a contextuality framework for continuous-variables. I am also studying simple quantum games where a quantum advantage arises.
photo Yao

Yao Ma



Keywords:
Cryptography, Hardware Security, Delegated Computing

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In delegated quantum computing or other various use cases, we want to build up a secure classical-only communication protocol in between server and client based on a trusted hardware device called Q-enclave. The encrypted quantum states information could be sent by client classically and Q-enclave on the server side could prepare the specific quantum states trustworthily.
photo Dominik

Dominik Leichtle



Keywords:
Quantum Cryptography, Post-Quantum Cryptography, Delegated Blind Quantum Computing, Verification of Quantum Computing, Provable Security

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We study the design and security of protocols involving tools from both quantum and post-quantum cryptography. In particular, our main interest concerns a class of protocols related to delegated quantum computing, including Classical-Client (Verified) Universal Blind Quantum Computing, and Quantum One-Time Programs.
photo Alexandru

Alexandru Cojocaru



Keywords:
Quantum Cryptography, Post-Quantum Cryptography, Delegated Blind Quantum Computing, Verification of Quantum Computing, Provable Security

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We study the design and security of protocols involving tools from both quantum and post-quantum cryptography. In particular, our main interest concerns a class of protocols related to delegated quantum computing, including Classical-Client (Verified) Universal Blind Quantum Computing, and Quantum One-Time Programs.
photo Leo

Léo Colisson



Keywords:
Quantum Cryptography, Post-Quantum Cryptography, Delegated Blind Quantum Computing, Verification of Quantum Computing, Provable Security

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We study the design and security of protocols involving tools from both quantum and post-quantum cryptography. In particular, our main interest concerns a class of protocols related to delegated quantum computing, including Classical-Client (Verified) Universal Blind Quantum Computing, and Quantum One-Time Programs.
photo Daniel

Daniel Mills



Keywords:
Quantum Computational Supremacy, Verification, Benchmarking, NISQ Technology, Classical Simulation of Quantum Systems, Quantum Computing Software

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Dan’s work aims to facilitate the expedited development of powerful quantum computing devices. His chosen route for doing so is through the use of verification to measure the success of a quantum computing device in implementing quantum computations, allowing for the guidance of future developments to improve the chances of success. This includes through measuring the impact of experimental noise, optimising control software, and creating tests for quantum computational supremacy.
photo Sima

Sima Bahrani



Keywords:
Benchmarking, Quantum Networks, Quantum Protocol Zoo

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Our objective is to benchmark the performance of various quantum protocols such as quantum money and anonymous transmission. We work on defining suitable figure of merits for quantum protocols, especially in a network setting.
photo Brian

Brian Coyle



Keywords:
Quantum machine learning, quantum advantage, testing, variational algorithms, device independent cryptography

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I am broadly interested in all aspects of quantum machine learning and quantum learning theory, in particular in finding quantum speedups or advantages in this area. Specifically, I have worked on distribution learning and generative modelling and their relationships to distribution testing.
I have also investigated hybrid quantum-classical models known as variational quantum circuits (similar to a classical neural network) as applications in machine learning and more generally in quantum algorithm discovery. These are suitable for near term quantum devices as they require a minimal quantum overhead, with the heavy lifting done by a classical processor to help the quantum model learn so solve a particular problem. They are also somewhat tolerant to destructive quantum noise which can kill any advantage in practice. In particular, we have studied them as generative models in a form called a ‘Born machine’ and as quantum classification models. Mostly, these are implemented using the Rigetti Forest quantum platform, and have been run on real quantum hardware.

Papers:
Robust Data Encodings for Quantum Classifiers: ArXiv to appear.
The Born Supremacy: Quantum Advantage and Training of an Ising Born Machine https://arxiv.org/abs/1904.02214.
Certified Randomness From Steering Using Sequential Measurements: https://www.mdpi.com/2410-387X/3/4/27.
One-Sided Device-Independent Certification of Unbounded Random Numbers: https://arxiv.org/abs/1806.10565v2.
photo Rawad

Rawad Mezher



Keywords:
Quantum randomness / Quantum Supremacy / Verification of near-term quantum devices

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During my PhD I worked on finding new ways to generate a useful form of quantum randomness known as a unitary t-design. Unitary t-designs have many useful applications, particularly in benchmarking of near-term quantum devices, as well as useful applications in quantum cryptography. I have also worked on using t-designs to construct shallow quantum circuits (which may be implementable experimentally in the near term) demonstrating a quantum supremacy. I’ve also shown that these circuits can be made robust to noise, while maintaining their shallow depth, and therefore their experimental practicality.
Recently, my research has shifted towards verification of near term quantum devices either currently doable experimentally, or expected to be implemented in the near-term.
photo Paul

Paul Hermouet



Keywords:
Quantum advantage, Cryptography, Protocol Zoo, device independent cryptography

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In the classical world, there are strong result about possibilities and impossibilities of the secure realization of several multi-party protocols. Quantum computation provides new ways of sending information and thus new ways of implementing these protocols, but also new means for an attacker to break them, which leads to new possibilities/impossibilities results.
I work on making a survey as exhaustive as possible on these possibilities/impossibilities results and what advantages have quantum protocols over the classical ones.
photo Armando

Armando Angrisani



Keywords:
Quantum machine learning, quantum advantage, privacy-preserving machine learning, generative models, statistical learning theory

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My goal is to design effective quantum machine learning algorithms for Noisy Intermediate-Scale Quantum (NISQ) devices. This task poses challenging questions in quantum complexity and statistical learning theory, as we wish to prove a quantum advantage both in terms of time and sample complexity. Moreover, I am interested in secure delegation protocol for machine learning algorithms. NISQ devices will be remotely available to clients, thus privacy-preserving delegation protocols are crucial when the input contains personal (e.g. biometric) information. I am interested as well in classical machine learning problems, such as clustering and generative modelling.
photo Niraj

Niraj Kumar



Keywords:
Quantum machine learning, benchmarking and verification of quantum computation, secure communications.

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I am working on quantifying resources for quantum communication protocols (Equality, Euclidean Distance, Hidden matching to name a few) and drawing a comparison with their classical analogue. The work also involves experimental implementation to try to demonstrate quantum superiority. My other interests include quantum games, complexity.
photo Luka

Luka Music



Keywords:
Quantum cryptography, secure multiparty quantum computing.

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DETAILS

Former Members



Nathansh Mathur
Rhea Parekh
Castagnet Cyril