About
I am a CNRS research scientist at IRIF, Université Paris Cité. I received my PhD from École Normale Supérieure de Paris (ENS) in November 2017, under the supervision of David Pointcheval and Hoeteck Wee. In 2017 – 2019, I was a postdoctoral researcher at Karlsruhe Institute of Technology (KIT), in the team of Dennis Hofheinz.
My main research interests are secure multiparty computation and zero-knowledge proofs (both foundational and practical aspects), as well as the theoretical foundations of cryptography. For an up-to-date list of my publications, you can check my publication page, my dblp profile, or my Google scholar profile. All my publications become available at some point in open access format on the ePrint archive; see the list here. Here are links to my PhD thesis and my HDR manuscript.
News
Archived
June 2024: The Algorithms & Complexity team at IRIF (CNRS, Université Paris-Cité) in Paris, France is inviting applications for several fully-funded postdoctoral positions (1–2 years) to work on cryptography. Areas of interest include, but are not limited to, zero-knowledge proofs, secure computation, post-quantum cryptography, foundations of cryptography, connections with complexity theory, confidential transactions, anonymous credentials. The candidate will work alongside Geoffroy Couteau and Michele Orrù.
- Required qualifications. The ideal candidate for the postdoc position will hold a PhD (or be close to completion) in cryptography and be an expert in any of the areas of interest.
- Salary. €3080 to €4291 gross monthly salary depending on the past experience of the candidate.
- Dates. The starting date is flexible from October 2024.
- Working at IRIF, Paris: IRIF (the computer science department of Université Paris Cité) is a French institute focused on foundational computer science. It provides a stimulating environment with researchers from many areas of theoretical computer science. CNRS is the largest European research institution.
Update (August 2024): this opening is now closed! You can still check the link above to be informed about other positions at IRIF in the Algorithm and Complexity group, now or in the future (the page is updated regularly).
March 2024: I defended my Habilitation à Diriger des Recherches on March 20. An HDR is a French diploma needed to supervize PhD students (without it, a co-supervisor with HDR is required). It proceeds essentially like a second PhD defense. You can find my HDR manuscript here; it provides an overview of secure computation in the correlated randomness model, and a step-by-step introduction to pseudorandom correlation generators, which might be useful for anyone wanting to get into this research area. More information about the defense here.
September 2023: I was awarded an ERC Starting Grant for my project OBELiSC (Overcoming Barriers and Efficiency Limitations in Secure Computation). See here and here for interviews where I explain (in French) the goals of the project, and here for a short abstract (still in French).
June 2023: I was invited to deliver a Spotlight Talk to the 2023 Conference on Information-Theoretic Cryptography (ITC). My talk, titled On Correlated Pseudorandomness, covered pseudorandom correlation generators, their impact on secure computation, and some of the latest advances in the area. You can check the slides here.
April 2022: Our Eurocrypt'22 paper, On Building Fine-Grained One-Way Functions from Strong Average-Case Hardness, has been invited to the Journal of Cryptology. In this work, we prove weak feasibility results and strong barriers for basing extremely limited forms of cryptography on powerful average-case hardness assumptions. Working on this paper has been a long, but thrilling journey with my amazing coauthor, Chris Brzuska.
January 2022: We just completed a book chapter for an upcoming book with Elette Boyle, Niv Gilboa, and Yuval Ishai. It is an up-to-date overview of homomorphic secret sharing, function secret sharing, and some of their many applications (including pseudorandom correlation generators). Check it out!
Resources
This website contains a few posts which might be useful to students in cryptography, gathered in the blog section. It includes in particular:
- A LaTeX template for writing research papers in cryptography;
- A probability cheat sheet, with basic tools and results that I believe should be part of the cryptographer’s toolbox;
- A Q&A section, where I gathered some of my answers to common questions on the cryptography stackexchange.
Students and postdocs
I currently have very limited bandwidth to take on new postdocs or PhD students. However, I can always be persuaded to make room for one more if I see strong potential for exciting collaborations. Topics of interest include, but are not limited to, secure computation, zero-knowledge proofs, post-quantum cryptography, code-based cryptography, and foundational aspects of cryptography (including fine-grained cryptography, black-box separations, and connections to learning theory).
Postdocs
| Time period | Notes | |
|---|---|---|
| Kaartik Bhushan | Jun. 2025 – current | |
| Nikolas Melissaris | Mar. 2025 – current | |
| Ulysse Léchine | Jan. 2025 – current | |
| Lennart Braun | Jan. 2025 – current | |
| Ioanna Karantaidou | Jan. 2025 – current | Co-hosted with Michele Orrù |
| Sihang Pu | Apr. 2024 – current | |
| Christop Egger | Oct. 2022 – Oct. 2024 | Now Assistant Professor at Chalmers University of Technology |
| Alexander Koch | Oct. 2022 – Feb. 2025 | Now Cryptography Expert and Consultant at Secorvo Security Consulting |
| Balthazar Bauer | Oct. 2022 – Sep. 2023 | Now holding the Chaire de Professeur Junior at UVSQ |
| Sven Maier | Nov. 2022 – Mar. 2023 | Currently Research Engineer at Wibu Systems |
PhD students
| Time period | Notes | |
|---|---|---|
| Elahe Sadeghi | Oct. 2024 – | Decentralized Wallets from Fast Threshold Signing (co-advised with Sriram Vishwanath) |
| Dung Bui | Oct. 2021 – Mar. 2025 | Efficient Secure Computation from Correlated Pseudorandomness. Now postdoc at QI team, LIP6, Sorbonne Université. You can check Dung’s PhD thesis here. |
| Clément Ducros | Oct. 2021 – Nov. 2024 | Multiparty Computation from the Hardness of Coding Theory (co-advised with Alain Couvreur). You can check Clément’s PhD thesis here. |
| Eliana Carozza | Oct. 2021 – Mar. 2025 | Code-Based Post-Quantum Signature Schemes: from MPC-in-the-Head to Threshold Signatures (co-advised with Antoine Joux). Now educational designer and researcher at UVSQ. You can check Eliana’s thesis here. |
| Ulysse Léchine | Oct.2021 – Dec. 2024 | Complexity theory: medley (co-advised with Thomas Seiller). Now postdoc at IRIF. You can check Ulysse’s PhD thesis here. |
| Pierre Meyer | Sep. 2020 – Sep. 2023 | Secure computation with constrained communication (co-advised with Elette Boyle). Now postdoc at Aarhus University. You can check Pierre’s PhD thesis here. |
Master students
| Time period | Notes | |
|---|---|---|
| Alexandros Themelis | Apr. 2024 – Sep. 2024 | Advanced Post-Quantum Signatures. Co-supervised witn Sihang Pu. |
| Dung Bui | Mar. 2021 – Aug. 2021 | Batch equality tests and secure comparison from pseudorandom correlation generators. Dung’s work led to a paper, presented at PKC’23. |
| Clément Ducros | Mar. 2021 – Aug. 2021 | Secure computation meets linear-time encodable codes. Clément’s work led to a paper, presented at PKC’23. |
| Michael Reichle | Feb. 2020 – Aug. 2020 | Efficient range proofs with transparent setup from bounded integer commitments. Michael’s work led to a paper, presented at EUROCRYPT’21. Now postdoc at ETH Zurich under the supervision of Dennis Hofheinz. |
| Dominik Hartmann | Feb. 2019 – Aug. 2019 | Compilers for non-interactive zero-knowledge proofs. Dominik’s work led to a paper, presented at CRYPTO’20. Now PhD student at Ruhr Universität Bochum. |
Other: long-term visitors, interns, bachelor students
| Time period | Status | Notes | |
|---|---|---|---|
| Amit Agarwal | Apr. 2025 – May 2025 | Visiting PhD student |
|
| Xiaxi Ye | Apr. 2025 – Aug. 2025 | Visiting PhD student |
|
| Kaartik Bhushan | Nov. 2024 – Feb. 2024 | Visiting PhD student |
Now postdoctoral researcher at IRIF. |
| Francesco Migliaro | Nov. 2024 – Apr. 2025 | Visting PhD student |
|
| Mahshid Riahinia | Sep. 2024 – Sep. 2025 | Visiting postdoctoral researcher | |
| Naman Kumar | June 2024 – Sep. 2024 | Internship | Naman’s visit led to a paper presented at EUROCRYPT’25 |
| Aditya Hegde | June 2024 – July 2024 | Internship | Aditya’s visit led to three papers presented at EUROCRYPT’25. |
| Willy Quach | Feb. 2024 – May 2024 | Visiting postdoctoral researcher | Willy’s visit led to a paper presented at TCC’24. |
| Kelsey Melissaris | Feb. 2024 – Jun. 2024 | Visiting postdoctoral researcher | |
| Nikolas Melissaris | Feb. 2024 – Jun. 2024 | Visiting PhD student |
Nikolas’ visit led to a paper, to be presented at RANDOM’25. Now postdoctoral researcher at IRIF. |
| Sacha Servan-Schreiber | Sep. 2023 – March 2024 | Visiting PhD student |
Sacha’s visit led to two papers, presented at ASIACRYPT’24. |
| Naman Kumar | May 2023 – Jun. 2023 | Internship | Naman’s work led to a paper, to be presented at CRYPTO’24. |
| Elahe Sadeghi | Jun. 2022 – Jul. 2022 | Visiting PhD student |
Elahe’s work led to a paper, presented at EUROCRYPT’23. |
| Milan Gonzalez-Thauvin | May 2021 – Jul. 2021 | Internship | Constructions of Non-Interactive Zero-Knowledge Proofs: Efficiency and Generality |
| Maryam Zarezadeh | Nov. 2020 – Apr. 2021 | Visiting PhD student |
Non-interactive inner products from LPN. Maryam’s work led to a paper, presented at ASIACRYPT’22. |
| Elahe Sadeghi | Jul. 2020 – Oct. 2020 | Internship | Statistical ZAPs from group-based assumptions. Elahe’s work led to a paper, presented at TCC’21. |
| Pierre Meyer | Nov. 2020 – Jan. 2020 | Internship | Breaking the circuit size barrier for secure computation under quasi-polynomial LPN. Pierre’s work led to a paper, presented at EUROCRYPT’21. |
| Sebastian Faller | Oct. 2018 – Feb. 2019 | Bachelor | Lattice-based implicit zero-knowledge arguments. Now PhD student at ETH Zurich under the supervision of Dennis Hofheinz and Julia Hesse. |
| Michael Reichle | May 2018 – Sep. 2018 | Bachelor | Non-interactive keyed-verification anonymous credentials. Michael’s work led to a paper, presented at PKC’19. Now postdoc at ETH Zurich under the supervision of Dennis Hofheinz. |
| Samuel Kopmann | Nov. 2017 – Mar. 2018 | Bachelor | Improved designated-verifier non-interactive zero-knowledge arguments |
Program Committees
The list of conferences, workshops, and journals where I served as a member of the program committee (conferences, workshops) or editorial board (journals).
| Year | Venues |
|---|---|
| 2025 | EUROCRYPT (area chair: advanced cryptographic primitives) |
| 2024 | Communications in Cryptology, TCC |
| 2023 | CSF, CRYPTO |
| 2022 | PKC, CSF, SCN, TCC |
| 2021 | EUROCRYPT, IWSEC, WAHC |
| 2020 | EUROCRYPT, IWSEC, WAHC |
| 2019 | TCC, WAHC |
| 2018 | INDOCRYPT |