About me

I am a Research Associate working on cryptographic applications in the King’s Cryptographers group at King’s College London.

Research interests

I am interested in investigating and developing secure and practical cryptographic primitives.

My main research topic is analysing the concrete security of cryptographic primitives and protocols. This includes estimating and experimentally verifying the cost of classical and quantum cryptanalytic attacks and constructing security proofs. Most of my work in this direction has focused on constructions claiming post-quantum security.

I also research some aspects of cryptographic implementations, including the development of techniques to investigate their correctness, and the extension of the use of cryptographic co-processors beyond their original scope.

Other interests

Beyond research, I also enjoy teaching. I recently published an early version of a set of lecture notes in provable cryptography in Spanish, in the hope of helping spread cryptography the “science” (vs the “art”) also in the Southern Cone and in other Spanish-speaking countries: https://apuntes.indcpa.com

Previous positions

In 2024, I was a visiting scholar at the department of computing of the Universidad de Buenos Aires, where I taught a course on modern cryptography.

Between 2023 and 2024, I was a post-doctoral researcher working on cryptographic applications at Universidade NOVA de Lisboa / NOVA LINCS.

Between 2022 and 2023, I was a Research Scientist at Intel Labs, working on post-quantum cryptography.

Prior to joining Intel, I was a post-doctoral researcher at the Applied Cryptography Group at ETH Zürich, working with Kenny Paterson, and a fellow of the Zürich Information Security & Privacy Center, ZISC.

In 2021, I graduated with a PhD from the Information Security Group at Royal Holloway, University of London, under the supervision of Martin R. Albrecht. My doctoral research focused on theoretical and practical aspects of post-quantum cryptography and cryptanalysis.

During the summer of 2019, I interned at Microsoft Research in the Security and Cryptography group under the joint supervision of Michael Naehrig and Martin Roetteler. During the summer of 2018, I interned in the same group under the supervision of Craig Costello.

Before joining Royal Holloway, I obtained a BSc in Mathematics and an MSc in Applied Mathematics, both from Imperial College London. For a while, I also worked as a NodeJS developer.

My academic CV can be downloaded here, my professional one can be downloaded here.

Publications

• N. Bindel, X. Bonnetain, M. Tiepelt, F. Virdia, Quantum Lattice Enumeration in Limited Depth, Crypto 2024, eprint ²⁰²³⁄₁₄₂₃, code, DOI
• F. Virdia, Popping “R-propping”: breaking hardness assumptions for matrix groups over F_{2^8}, Mathematical Cryptology, 3(1), eprint ²⁰²³⁄₁₄₂₅, code, bibtex
• M. Filić, K. G. Paterson, A. Unnikrishnan, F. Virdia, Adversarial Correctness and Privacy for Probabilistic Data Structures, ACM CCS 2022, eprint ²⁰²²⁄₁₁₈₆, code, DOI
• F. Virdia, Post-Quantum Cryptography: Cryptanalysis and Implementation, doctoral thesis, download, bibtex
• E. W. Postlethwaite, F. Virdia, On the Success Probability of Solving Unique SVP via BKZ, PKC 2021, eprint ²⁰²⁰⁄₁₃₀₈, code, DOI
• S. Jaques, M. Naehrig, M. Roetteler, F. Virdia, Implementing Grover oracles for quantum key search on AES and LowMC, Eurocrypt 2020, eprint ²⁰¹⁹⁄₁₁₄₆, code, DOI
• JP. D’Anvers, M. Rossi, F. Virdia, (One) failure is not an option: Bootstrapping the search for failures in lattice-based encryption schemes, Eurocrypt 2020, eprint ²⁰¹⁹⁄₁₃₉₉, code, DOI
• C. Costello, P. Longa, M. Naehrig, J. Renes, F. Virdia, Improved Classical Cryptanalysis of SIKE in Practice, PKC 2020, eprint ²⁰¹⁹⁄₂₉₈, code, DOI
• M. R. Albrecht, C. Hanser, A. Hoeller, T. Pöppelmann, F. Virdia, and A. Wallner, Implementing RLWE-based Schemes Using an RSA Co-Processor, CHES 2019, eprint ²⁰¹⁸⁄₄₂₅, code, CSAW finalist, DOI
• M. R. Albrecht, B. R. Curtis, A. Deo, A. Davidson, R. Player, E. W. Postlethwaite, F. Virdia, and T. Wunderer, Estimate All the {LWE, NTRU} Schemes!, SCN 2018, eprint ²⁰¹⁸⁄₃₃₁, website, code, DOI
• M. R. Albrecht, F. Göpfert, F. Virdia, and T. Wunderer, Revisiting the expected cost of solving uSVP and applications to LWE, Asiacrypt 2017, eprint ²⁰¹⁷⁄₈₁₅, code, DOI

Preprints

• G. Fenzi, J. Gilcher, F. Virdia, Finding Bugs and Features Using Cryptographically-Informed Functional Testing, eprint ²⁰²⁴⁄₁₁₂₂, code
• M. Filić, F. Virdia, A note on securing insertion-only Cuckoo filters, eprint ²⁰²⁴⁄₅₂₀
• T. Hanson, Q. Wang, S. Ghosh, F. Virdia, A. Reinders, M. Sastry, Optimization for SPHINCS+ using Intel Secure Hash Algorithm Extensions, eprint ²⁰²²⁄₁₇₂₆

Teaching material

• F. Virdia, ApuntES de Criptografía, lecture notes (in Spanish)

Talks

• Securing semi-open group messaging

  • Cryptographic Applications Workshop (CAW 2024), 26/05/2025, slides

• Quantum Lattice Enumeration in Limited Depth

  • MSR, 16/08/2024, slides
  • London-ish Lattice Coding & Crypto Meeting, 01/12/2023, slides

• (Some) quantum speedups are… |alive〉+ |dead〉

  • Latincrypt 2023 invited talk, 06/10/2023, slides

• Criptografía post-cuántica, desafíos y direcciones de investigación

  • Seminario UNC, 25/10/2023, slides
  • INCA Crypto, 30/09/2023, slides
  • Seminario UBA, 03/06/2022, slides

• On the Success Probability of Solving Unique SVP via BKZ

  • PKC 2021, video, Q&A, slides

• Quantum programming languages for cryptanalysis

  • IBM QT Science meeting, 15/04/2021, slides

• Concrete security estimates and parameter selection for LWE-based schemes

  • PROMETHEUS H2020 Annual meeting, 25/11/2020, slides

• Implementing Grover oracles for quantum key search on AES and LowMC

  • Eurocrypt 2020, video, Q&A, slides
  • Schloss Dagstuhl, Quantum Cryptanalysis seminar 2019, 17/10/2019, slides

• Implementing RLWE-based Schemes Using an RSA Co-Processor

  • COSIC Seminar, 21/10/2019, video, slides
  • CHES 2019, 26/08/2019, video, slides
  • London Lattice Coding & Crypto Meeting, 23/01/2019, slides

• Estimate all the {LWE, NTRU} schemes!

  • ENS Lyon Lattice and Crypto meetings, 01/03/2018

• Revisiting the Expected Cost of Solving uSVP and Applications to LWE

  • Asiacrypt 2017, video, slides
  • ENS Lyon Lattice and Crypto meetings, 21/09/2017

• Post-Quantum Cryptography standards

  • ESC 2019, 20/09/2019, slides

Scientific activity

• Program Committee member: CYSARM 2020, CT-RSA 2021, CT-RSA 2022, AFRICACRYPT 2022, EUROCRYPT 2023, LATINCRYPT 2023, AFRICACRYPT 2024, ISC 2024, IEEE S&P 2025 (Cycle 2), AFRICACRYPT 2025, LATINCRYPT 2025
• Cryptography Schools: INCA Crypto
• Session chair: LATINCRYPT 2023

Teaching

• Teaching assistant: Information Security (BSc course, spring semester 2022, ETH Zurich), Information Security Lab (MSc course, autumn semester 2021, ETH Zurich)
• Lab assistant: Applications of Cryptography (MSc course, autumn semester 2019, Royal Holloway)