Supervision : Elham KASHEFI

Co-supervision : JOUX Antoine

Study of Protocols between Classical Clients and a Quantum Server

Given the pace at which quantum hardwares evolve, Society will surely face a problem to solve. Imagine a few opulent quantum servers Admired by the crowd of classical users. Among them—can you see?—the poor Alice crying: "This computer is too slow, what a bad timing!" With a malicious sight, a rich quantum server Kindly comes to Alice, offering to serve her. But to the humble Alice, can we guarantee That the price to pay, won't be her liberty? Throughout this thesis, carefully, we will ensure The computation, to the server stays obscure. To lighten our walkway, we will craft a candle That classically counterfeits a quantum channel. To strike the fatal blow against the terror We require the help of "Learning With Errors". Sadly we uncover an abrupt disclosure: No such protocols are composably secure. In our quest of equity, we got a surprise: Multiple clients can together socialize And on quantum states we can prove non-trivial facts With a single message, keeping the state intact.

2018-2024 Publications

• 2024
  • L. Colisson, D. Markham, R. Yehia : “All graph state verification protocols are composably secure”, (2024)
• 2022
  • L. Colisson : “Etude des protocoles entre clients classiques et serveur quantique”, thesis, phd defence 03/28/2022, supervision Kashefi, Elham, co-supervision : Joux, Antoine (2022)
• 2021
  • L. Colisson, F. Grosshans, E. Kashefi : “Non-Destructive Zero-Knowledge Proofs on Quantum States, and Multi-Party Generation of Authorized Hidden GHZ States”, (2021)
• 2020
  • Ch. Badertscher, A. Cojocaru, L. Colisson, E. Kashefi, D. Leichtle, A. Mantri, P. Wallden : “Security Limitations of Classical-Client Delegated Quantum Computing”, Asiacrypt 2020, Virtual Event, Korea, Republic of (2020)
• 2019
  • A. Cojocaru, L. Colisson, E. Kashefi, P. Wallden : “QFactory: classically-instructed remote secret qubits preparation”, Advances in Cryptology – ASIACRYPT 2019, vol. 11921, Lecture Notes in Computer Science, Kobe, Japan, pp. 615-645, (Springer) (2019)
• 2018
  • A. Cojocaru, L. Colisson, E. Kashefi, P. Wallden : “On the possibility of classical client blind quantum computing”, 8^th International Conference on Quantum Cryptography, Shanghai, China (2018)