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.
Open Source

Lattigo is a multiparty homomorphic encryption (MHE) library in Go.
It implements several homomorphic encryption schemes and their multiparty variants.

Helium is an MHE-based secure multiparty computation (MPC) framework.
It builds on top of Lattigo and gRPC, and enables low-requirement MPC.
Teaching & Service
Teaching, as main instructor:
Fall 2025: | Computing on Encrypted Data (Master, 6 ECTS) @ Hasso Plattner Institute |
Summer 2025: | Intro. to Lattice-based Homomorphic Encryption @ EPFL-ETH Summer School on Lattice-based Cryptography |
Fall 2024: | Computing on Encrypted Data (Master, 3 ECTS) @ Hasso Plattner Institute |
Program committees:
EuroS&P 2025 CCS 2025 USENIX Security 2026
Publications
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Accurate and Composable Noise Estimates for CKKS with Application to Exact HE Computation
Jean-Philippe Bossuat, Anamaria Costache, Christian Mouchet, Lea Nürnberger, and Juan Ramón Troncoso-Pastoriza
COMMUNICATION IN CRYPTOLOGY, Vol. 2, 2025
[eprint] -
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
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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
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Helium: Scalable MPC among Lightweight Participants and under Churn
- ACM CCS 2024, Salt Lake City – 17 October 2024
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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
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Lattigo: a Multiparty Homomorphic Encryption Library in Go
- WAHC'20 – Workshop on Encrypted Computing & Applied Homomorphic Cryptography, Virtual – 15 December 2020