Ludovic Barman

Hi, I'm Ludovic!

I'm a software engineer and security researcher based in Zürich. I love building software, in particular when related to security, cryptography and networking.

I recently started working on AI Security at Google DeepMind. This feels like one of the next big problems in cybersecurity, and I'm thrilled to join this effort.

Previously, I worked on the security of the Android operating system at Google. I developed features related to end-to-end encryption, verifiable sandboxes, cross-device key management protocols, and network security features. I really enjoyed learning how to write software at scale and improve the safety of all Android users.

Before that, I completed a PhD at EPFL with Jean-Pierre Hubaux and Bryan Ford. I worked on the analysis and protection of communication metadata (e.g., website fingerprinting) and the design of anonymous communication networks. My favorite part was designing and scaling a mixnet for messaging apps (Groove). I co-designed Padmé, a padding function now deployed in Apple iMessage and Meta WhatsApp / Messenger.

In my free time, you'll find me hiking in the Alps or bouldering.

Feel free to reach out!

Research

Evaluating practical QUIC website fingerprinting defenses for the masses 2023
S. Siby, L. Barman, C. Wood, M. Fayed, N. Sullivan, C. Troncoso. PETS 2023
paper code
Groove: Flexible Metadata-Private Messaging 2022
L. Barman, M. Kol, D. Lazar, Y. Gilad, N. Zeldovich. OSDI 22
paper slides
Every Byte Matters: Traffic-Analysis of Bluetooth Wearable Devices (Distinguished Paper Award) 2021
L. Barman, A. Dumur, A. Pyrgelis, J-P. Hubaux. Ubicomp 2021
paper code press article
Decentralized Privacy-Preserving Proximity Tracing (DP3T) 2020
C. Troncoso et al. (DP3T Consortium)
paper Reuters BBC Financial Times Blick Le Temps
PriFi: Low-Latency Metadata Protection for Organizational Networks 2020
L. Barman, I. Dacosta, M. Zamani, E. Zhai, A. Pyrgelis, B. Ford, J. Feigenbaum, J-P. Hubaux. PETS 2020
paper code
Reducing Metadata Leakage from Encrypted Files and Communication with PURBs 2018
K. Nikitin & L. Barman, M. Underwood, W. Lueks, B. Ford, J-P. Hubaux. PETS 2019
paper slides press article code blog post
Mirror: Enabling Proofs of Data Replication and Retrievability in the Cloud 2015
F. Armknecht, L. Barman, J-M. Bohli, G. Karame. USENIX Security 2016
paper

Full list on Google Scholar

Blog posts

Secure Santa 2025
Securing Secret Santa with random oracles and Lehmer codes
Padmé: Efficiently Hiding File Sizes 2020
An inexpensive padding function to protect file sizes
IoT Home Automation with 3D-Printing 2019
Keeping fish and plants alive while away
A TLS Downgrade Attack with NetFilter Queues and Docker 2017
Hands-on MitM and protocol downgrade via NFQueues
A Journey into Stack Smashing 2017
Low-level binary exploitation, shellcoding, and bypasses