Roman Walch

Roman Walch

Co-founder/Lead Cryptographer at TACEO

TACEO

Biography

I am a co-founder and lead cryptographer at TACEO. Before that I obtained my PhD in Cryptography at Graz University of Technology. My main research interests include privacy enhancing technologies (FHE, MPC, ZKP), domain-specific symmetric primitives, and their application to real-world use cases.

Interests

  • Multiparty Computation (MPC)
  • Zero-Knowledge Proofs (ZKP)
  • (Fully) Homomorphic Encryption (FHE)
  • Post-Quantum Signatures
  • Efficient Implementations
  • Ciphers for MPC, FHE, and ZKP

Education

  • PhD in Computer Science (Cryptography), 2024

    Graz University of Technology

  • MSc in Information and Computer Engineering, 2019

    Graz University of Technology

  • BSc in Information and Computer Engineering, 2017

    Graz University of Technology

Featured Publications

Note: The standard convention in this discipline is to list the authors in alphabetical order.

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Large-Scale MPC: Scaling Private Iris Code Uniqueness Checks to Millions of Users

In this work we tackle privacy concerns in biometric verification systems that typically require server-side processing of sensitive …
Remco Bloemen, Bryan Gillespie, Daniel Kales, Philipp Sippl, Roman Walch
PDF Code

Monolith: Circuit-Friendly Hash Functions with New Nonlinear Layers for Fast and Constant-Time Implementations

Hash functions are a crucial component in incrementally verifiable computation (IVC) protocols and applications. Among those, recursive …
Lorenzo Grassi, Dmitry Khovratovich, Reinhard Lüftenegger, Christian Rechberger, Markus Schofnegger, Roman Walch
PDF Code

From Farfalle to Megafono via Ciminion: The PRF Hydra for MPC Applications

The area of multi-party computation (MPC) has recently increased in popularity and number of use cases. At the current state of the …
Lorenzo Grassi, Morten Øygarden, Markus Schofnegger, Roman Walch
PDF Code Slides

Pasta: A Case for Hybrid Homomorphic Encryption

The idea of hybrid homomorphic encryption (HHE) is to drastically reduce bandwidth requirements when using homomorphic encryption (HE) …
Christoph Dobraunig, Lorenzo Grassi, Lukas Helminger, Christian Rechberger, Markus Schofnegger, Roman Walch
PDF Code Slides

Privately Connecting Mobility to Infectious Diseases via Applied Cryptography

Recent work has shown that cell phone mobility data has the unique potential to create accurate models for human mobility and …
Alexandros Bampoulidis, Alessandro Bruni, Lukas Helminger, Daniel Kales, Christian Rechberger, Roman Walch
PDF Code Slides

Featured Talks

Quickly discover talks here.

Scaling Private Iris Code Uniqueness Checks to Millions of Users

Mar 25, 2025 RWMPC 2025
Slides

Private Shared State with CoSNARKs: Noir meets MPC

In this talk, we’ll dive into the world of collaborative SNARKs—what they are, the unique challenges they tackle, and what they are …
Nov 11, 2024 Devcon 7 - Bangkok
Slides

Collaborative SNARKs - Co-Circom

In this talk we present collaborative SNARKs and why they are needed. Furthermore, we present our co-circom library, a rust library …
Jul 24, 2024 Privacy & Scaling Exploration Residency Tokyo
Slides

Hash Functions Monolith for ZK Applications: May the Speed of SHA-3 be With You

The rising popularity of computational integrity protocols has led to an increased focus on efficient domain-specific hash functions, …
Sep 20, 2023 ZK Summit 10 -- London, UK
Slides

Teaching

I was involved with the following courses at TU Graz:

I also had the pleasure to (co-)supervise various bachelor’s and master’s thesis:

  • Patrick Schwarz: Privacy Preserving Machine Learning (co-supervised with Lukas Helminger)
  • Mathias Oberhuber: Implementation of ECDSA and MiMC with Minimal Overhead on Hardware (co-supervised with Markus Schofnegger)
  • Jakob Feiner: Lightweight Communication for Secure Outsourced Homomorphic Computation
  • Shibam Mukherjee: Privacy Preserving Recommender Systems
  • Roman Holler: Fitting Huge Datasets into Zero-Knowledge Proof Systems
  • Peter Waldert: Secure Classification as a Service
  • Fabian Schmid: Multi-Key Homomorphic Encryption in SEAL
  • Florian Lackner: Evaluating Multi-key Homomorphic Encryption in Federated Learning (co-supervised with Mathias Böhm)
  • Simon Guggi: Outsourcing Beaver Triple Generation for Multi-Party Computation to the Cloud (co-supervised with Fabian Schmid)

Contact