Guilhem Niot | PQShield, University of Rennes
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Guilhem Niot

PhD Student, Major Cybersecurity and Cryptography
PQShield, University of Rennes
guilhem (at) gniot.fr


About me Publications Awards Talks Projects Blog

About Me

I am a researcher at PQShield. I recently completed my PhD there under the supervision of Thomas Prest (PQShield) and Pierre-Alain Fouque (Université de Rennes). Before that, I graduated from ENS Lyon, France, and EPFL, Switzerland, with a double Master’s degree in Computer Science.

My work focuses on cybersecurity and cryptography, with a particular interest in privacy, applied cryptography, and software security. I enjoy working across a wide range of topics, from analysing the security of protocols and building efficient, secure software to designing theoretical yet practical cryptographic schemes.

Check my resume to learn more about my background.

Research Interests

  • Cryptography: protocol design, cryptography engineering
  • Cybersecurity: pen-testing, threat modelling

Preprints

  1. Proving Threshold Regev PKE from Adaptive Hint-MLWE: Efficient, Non-interactive, and CCA Secure
    Yisol Hwang, Shuichi Katsumata, Seonhong Min, Guilhem Niot, Yongsoo Song
  2. Key-Recovery Attacks on TALUS: A Cryptanalytic Note
    Guilhem Niot

Publications

2026

  1. Hermine: An Efficient Lattice-based FROST-like Threshold Signature
    Giacomo Borin, Sofia Celi, Rafael del Pino, Thomas Espitau, Shuichi Katsumata, Guilhem Niot, Thomas Prest, Kaoru Takemure
    ASIACRYPT 2026
  2. Optimizing and Implementing Threshold MAYO
    Diego Aranha, Giacomo Borin, Sofia Celi, Guilhem Niot
    CHES 2026
  3. Efficient Threshold ML-DSA
    Sofia Celi, Rafael del Pino, Thomas Espitau, Guilhem Niot, Thomas Prest
    USENIX Security 2026
  4. Lattice-based Threshold Blind Signatures
    Sebastian Faller, Guilhem Niot, Michael Reichle
    S&P 2026
  5. Revisiting PQ WireGuard: A Comprehensive Security Analysis With a New Design Using Reinforced KEMs
    Keitaro Hashimoto, Shuichi Katsumata, Guilhem Niot, Thom Wiggers
    S&P 2026
  6. Adaptively-Secure Three-Round Threshold Schnorr from DL
    Guilhem Niot, Michael Reichle, Kaoru Takemure
    EUROCRYPT 2026

2025

  1. Subversion-resilient Key-exchange in the Post-quantum World
    Kévin Duverger, Pierre-Alain Fouque, Charlie Jacomme, Guilhem Niot, Cristina Onete
    ACM CCS 2025
  2. Unmasking TRaccoon: A Lattice-Based Threshold Signature with An Efficient Identifiable Abort Protocol
    Rafael del Pino, Shuichi Katsumata, Guilhem Niot, Michael Reichle, Kaoru Takemure
    CRYPTO 2025
  3. Comprehensive Deniability Analysis of Signal Handshake Protocols: X3DH, PQXDH to Fully Post-Quantum with Deniable Ring Signatures
    Shuichi Katsumata, Guilhem Niot, Ida Tucker, Thom Wiggers
    USENIX Security 2025
  4. Practical Deniable Post-Quantum X3DH: A Lightweight Split-KEM for K-Waay
    Guilhem Niot
    ACM ASIACCS 2025
  5. Finally! A Compact Lattice-Based Threshold Signature
    Rafael del Pino, Guilhem Niot
    PKC 2025
  6. Share the MAYO: thresholdizing MAYO
    Sofia Celi, Daniel Escudero, Guilhem Niot
    PQCrypto 2025

2024

  1. Flood and Submerse: Distributed Key Generation and Robust Threshold Signature from Lattices
    Thomas Espitau, Guilhem Niot, Thomas Prest
    CRYPTO 2024
  2. Plover: Masking-Friendly Hash-and-Sign Lattice Signatures
    Muhammed F. Esgin, Thomas Espitau, Guilhem Niot, Thomas Prest, Amin Sakzad, Ron Steinfeld
    EUROCRYPT 2024

2023

  1. Squirrels: An efficient and secure post-quantum signature scheme based on plain lattices
    Thomas Espitau, Guilhem Niot, Chao Sun, Mehdi Tibouchi
    National Institute of Standards and Technology (NIST), Additional Digital Signature Schemes, 2023
    PDF NIST listing Master thesis report

2022

  1. GoldFinger: Fast & Approximate Jaccard for Efficient KNN Graph Constructions
    Rachid Guerraoui, Anne-Marie Kermarrec, Guilhem Niot, Olivier Ruas, François Taïani
    IEEE/Transactions on Knowledge and Data Engineering (TKDE), 2022
    PDF Code 1 Code 2 Code 3 Internship report

PhD Thesis

  1. Achieving Practical Post-Quantum Threshold Signatures from Lattices
    Guilhem Niot
    PhD thesis, Université de Rennes, 2026

Awards

  • Received a $5000 grant from Public Good Crypto in 2025 for a project to distribute the ML-DSA digital signature.
  • Received the Kudelski Prize (1500CHF) from EPFL in 2024 for my master thesis on Squirrels. 𝕏 post

Talks

Migrating WireGuard to the Post-Quantum Setting

  • Migrating Protocols to the Post-Quantum Setting: The Case of WireGuard

Rackle

  • Rackle: Adaptively-Secure Three Round Threshold Schnorr from DL
    • EUROCRYPT 2026, Rome (11/05/2026) — PDF

Signal Handshake Protocols

  • A Comprehensive Study of Signal Handshake Protocols: X3DH, PQXDH to Fully Post-Quantum with Deniable Ring Signatures
    • Berkeley Security Seminar, Remote (03/12/2025) — PDF

Threshold ML-DSA & Signatures

  • The NIST MPTC Call: Post-Quantum Threshold Signatures and a Promising Approach to Threshold ML-DSA
    • Séminaire C2 (04/07/2026) — PDF
  • PhD Defense: Achieving Practical Post-Quantum Threshold Signatures from Lattices
    • ENS (19/05/2026) — PDF
  • Mithril: Efficient Threshold ML-DSA from Short Secret Sharing
    • NIST MPTS Workshop 2026 (28/01/2026) — PDF
    • NIST Sixth PQC Standardization Conference, Remote (25/09/2025) — PDF
    • JP Morgan AlgoCRYPT Seminar, New York (29/08/2025) — PDF
  • Lattice-based Threshold Blind Signatures
    • NIST MPTS Workshop 2026 (28/01/2026) — PDF
  • PQC + Threshold: State of the Art in Threshold Quantum-Resistant Signatures
    • CryptoDay @ Télécom Paris, Paris (18/09/2025) — PDF
  • Finally! A Compact Lattice-Based Threshold Signature
    • Journées C2 ‘25, Pornichet, France (04/2025) — PDF

Secret Sharing & Identifiable Aborts

  • Short Shares, Small Coefficients: A New Secret Sharing Scheme and its Applications to Lattice-based Threshold Cryptography
    • Almasty Seminar, LIP6, Sorbonne University, Paris (21/03/2025) — PDF
    • IBM Research Europe visit, Zurich (03/02/2025) — PDF
    • JP Morgan AlgoCRYPT Seminar, Remote (10/01/2025) — PDF
  • Identifiable Aborts in TRaccoon: Let’s introduce Short Secret Sharings
    • Journée PEPR PQ TLS, Paris (13/03/2025) — PDF
  • Secret Sharing Schemes for Lattice-Based Threshold Cryptography
    • Workshop on secret sharing schemes, satellite EUROCRYPT 2025, Tarragona (14/05/2025) — PDF
  • Beyond the Threshold: Detecting Aborts in Lattice-based Threshold Signature Schemes
    • Visit Cryptography and Privacy Lab, Seoul National University (03/12/2024) — PDF

Flood and Submerse

  • Flood and Submerse: Distributed Key Generation and Robust Threshold Signature from Lattices
    • ENSL/CWI/KCL/IRISA joint crypto seminar, Remote (30/09/2024) — PDF
    • CRYPTO 2024, Santa Barbara (19/08/2024) — PDF

Plover

  • Plover: Masking-Friendly Hash-and-Sign Lattice Signature
    • EUROCRYPT 2024, Zurich (30/05/2024) — PDF
    • CAPSLOCK Seminar, Rennes (05/04/2024) — PDF

Squirrels

  • Squirrels: a post-quantum signature scheme based on plain lattices
    • Journées C2 ‘23 (18/10/2023) — PDF
    • Master thesis defense (12/09/2023) — PDF

Other

  • Making KNN algorithms faster with GoldFinger, a Fast and Precise method for approximating Jaccard similarity
    • Master internship defense (08/2021) — PDF
  • Intel SGX enclaves
    • Bachelor internship defense (French) (08/2020) — PDF

Posters

  • Efficient Threshold ML-DSA
    • ACM CCS 2025 (10/2025) — PDF
  • Squirrels: Unstructured Lattice Digital Signature
    • NIST Fifth PQC Standardization Conference (04/2024) — PDF

Projects

  1. SACCHA: Dog model reproducing heart murmurs for training veterinary students.
    Elise Postic, Guilhem Niot, Alexandre Variengien, Simon Dupouy, Théo Regny
    PDF
  2. Mixed Feelings: Small game developed in 24h during the Orbital Game Jam 2022 at EPFL.
    Yann Aguettaz, Diego Dorn, Anita Dürr, Guilhem Niot, Alexandre Variengien
    Code
  3. NelmioApiDocBundle: Extension of PHP Framework Symfony to ease API documentation.
  4. Dolphin: a toy decentralized bill-sharing app. CRDTs for managing distributed data, and TreeKEM for Group Key Management and key rotations.
  5. Pingo: a π-calculus interpreter in G
  6. Modelling of impact of Covid tracing apps.
  7. Vice-president of AliENS, the IT association of ENS de Lyon (600 members) from 2020 until 2022.

Blog posts

Community Service

I was part of the program commitee for the following conferences:

  • CRYPTO 2027
  • CHES 2027
  • PKC 2027

I also sub-reviewed papers for the following conferences:

  • CRYPTO 2025
  • EUROCRYPT 2024, 2025,
  • ASIACRYPT 2025
  • PKC 2026
  • EURO S&P 2026
  • TCC 2024

and journals:

  • Designs, Codes and Cryptography 2025