Christian Mouchet

About me

Hey! I'm Christian, a PostDoc researcher and lecturer at HPI in the Cybersecurity - Identity Management group. Before that, I completed my PhD at EPFL, in the Security and Privacy Engineering Laboratory.

I'm interested in practical aspects of cryptographic protocols. My current research focuses on multiparty homomorphic encryption schemes and their applications to secure multiparty computation. I wrote a PhD thesis on the topic.

If you want to know more, here are my CV and my LinkedIn profile.

Activities

My most notable project is to co-develop and maintain Lattigo, a multiparty homomorphic encryption library in Go. Lattigo implements the latest generation of homomorphic encryption schemes and their multiparty variants.

I also recently released Helium, an MHE-based secure multiparty computation (MPC) framework. Helium builds on top of Lattigo and provides an interface for running multiparty computation over encrypted data.

In 2024-2025, I'm teaching the Computing on Encrypted Data master course at HPI, and I'm serving as a program committee member for EuroS&P 2025 and CCS 2025

Publications

• Helium: Scalable MPC among Lightweight Participants and under Churn
  Christian Mouchet, Sylvain Chatel, Apostolos Pyrgelis, and Carmela Troncoso
  ACM CCS 2024
  [eprint]
• PELTA – Shielding Multiparty-FHE against Malicious Adversaries
  Sylvain Chatel, Christian Mouchet, Ali Utkan Sahin, Apostolos Pyrgelis, Carmela Troncoso, and Jean-Pierre Hubaux
  ACM CCS 2023
  [eprint]
• An Efficient Threshold Access-Structure for RLWE-Based Multiparty Homomorphic Encryption
  Christian Mouchet, Elliott Bertrand, and Jean-Pierre Hubaux
  JOURNAL OF CRYPTOLOGY 2023
  [eprint]
• Multiparty homomorphic encryption from ring-learning-with-errors
  Christian Mouchet, Juan Troncoso-Pastoriza, Jean-Philippe Bossuat, and Jean-Pierre Hubaux
  PETS 2021
  [eprint]
• Efficient bootstrapping for approximate homomorphic encryption with non-sparse keys
  Jean-Philippe Bossuat, Christian Mouchet, Juan Troncoso-Pastoriza, and Jean-Pierre Hubaux
  EUROCRYPT 2021
  [eprint]
• Lattigo: A multiparty homomorphic encryption library in Go
  Christian Mouchet, Jean-Philippe Bossuat, Juan Troncoso-Pastoriza, and Jean-Pierre Hubaux
  WAHC 2020
  [paper]
• UnLynx: A Decentralized System for Privacy-Conscious Data Sharing
  David Froelicher, Patricia Egger, João Sá Sousa, Jean Louis Raisaro, Zhicong Huang, Christian Mouchet, Bryan Ford, and Jean-Pierre Hubaux
  PETS 2017
  [paper]

Talks

• Multiparty Homomorphic Encryption: from Theory to Practice
  
  • Invited Talk, TU Darmstadt, Germany – 07 April 2025
  • Invited talk, FHE:IDEAs Workshop @ EUROCRYPT 2024 – 25 May 2024
  • Invited talk, Vector Institute, Toronto – 02 October 2023
  • Invited talk, MIT, Boston – 11 October 2023
  • Invited talk, Hasso Plattner Institute, Potsdam – 22 September 2023
• Helium: Scalable MPC among Lightweight Participants and under Churn
  
  • ACM CCS 2024, Salt Lake City – 17 October 2024
• Computing across Trust Boundaries with Multiparty Homomorphic Encryption and the Lattigo Library
  
  • Invited talk, Workshop on Privacy Preserving systems, software and tools, Roma Tre University – 24 October 2022
  • Guest Lecture in Advanced Topics in Computer and Network Security, University of Padova – 27 October 2022
• Multiparty Homomrphic Encryption from Ring-Learning-with-Errors
  
  • PETS'21 – Privacy Enhancing Technologies Symposium, Virtual – 15 July 2021
• Lattigo: a Multiparty Homomorphic Encryption Library in Go
  
  • WAHC'20 – Workshop on Encrypted Computing & Applied Homomorphic Cryptography, Virtual – 15 December 2020