Dr. Christian Berger
Appointments by prior arrangement.
Research
My research addresses Byzantine fault tolerance (BFT) in distributed systems: How can a system keep operating reliably despite failures and targeted malicious behavior, while preserving consistency and progress at high performance and scale? To answer this, I design and analyze consensus and replication protocols, and evaluate them through large-scale simulations and targeted fault injection.- Byzantine fault tolerance and state machine replication
- Consensus algorithms
- Blockchain systems, distributed ledger technology, and decentralized finance (DeFi)
- Performance evaluation through network simulation and fault injection
Bio
I received my Bachelor’s (2014) and Master’s (2017) degrees in Computer Science from the University of Passau, Germany. From 2018 to 2019, I worked as an IT consultant at msg systems AG. In 2019, I joined the Chair of Security in Information Systems at the University of Passau as a research associate and PhD candidate under the supervision of Prof. Dr. Hans P. Reiser, where I worked in the research projects SORRIR and BFT2Chain. In 2024, I completed my doctorate (Dr. rer. nat., summa cum laude) with the thesis “Towards Fast and Adaptive Byzantine State Machine Replication for Planetary-Scale Systems”. Since January 2025, I have been a postdoctoral researcher (Akademischer Rat) at the Chair of System Software (Informatik 4) at FAU, led by Prof. Dr.-Ing. Rüdiger Kapitza.Awards
- Best Paper Runner-up, Middleware 2024 – for “Chasing Lightspeed Consensus: Fast Wide-Area Byzantine Replication with Mercury”
- Distinguished Paper Award, EDCC 2022 – for “Automatic Integration of BFT State-Machine Replication into IoT Systems”
- Prof. C.V. Ramamoorthy Best Paper Award, SRDS 2021 – for “Making Reads in BFT State Machine Replication Fast, Linearizable, and Live”
- Best Paper Candidate, SRDS 2019 – for “Resilient Wide-Area Byzantine Consensus Using Adaptive Weighted Replication”
- Teaching evaluation certificate of the Faculty of Engineering, FAU – 3rd place (of 13) in the seminar category, summer semester 2025
Research Projects
- NEMESIS – A Novel Evaluation Platform for Measuring Endurance of Byzantine Fault-Tolerant Systems under Injected Stressors DFG, October 2026 – September 2029 · Role: principal investigator
- BFT2Chain – Design and Validation of Scalable Byzantine Fault-Tolerant Consensus Algorithms for Blockchains DFG, 2021–2026, joint project of FAU and the University of Passau · Role: contributed to the proposal; researcher, later research lead
- SORRIR – A Self-Organizing, Resilient Execution Platform for IoT Services BMBF, 2019–2022 · Role: researcher, lead of major work packages
Teaching
- Winter semester 2026/27: Lecture Middleware – Cloud Computing
- Summer semester 2026: Lecture Distributed Systems
- Winter semester 2025/26: Lecture Middleware – Cloud Computing
- Summer semester 2025: Seminar Selected Chapters of System Software: Replicated Systems and Blockchain Systems; Exercise Distributed Systems
- Before 2025: Exercises in IT security and cloud security at the University of Passau
Academic Service
- Workshop organization: Local organizer of the ROBUST 2026 workshop (Resilient Operations – Byzantine Fault Tolerance and State-Machine Replication), Erlangen, October 2026
- Program committees: EDCC 2027 · DAIS 2026 · BRAINS 2026 · ROBUST 2026 · DAIS 2025 · OPODIS 2025 · ROBUST 2025
- Journal reviewing: IEEE Transactions on Dependable and Secure Computing · Journal of Parallel and Distributed Computing · Science of Computer Programming · Blockchain: Research and Applications · Computer Communications
- Grant reviewing: Swiss National Science Foundation (SNSF)
- Memberships: IEEE Computer Society · ACM · Gesellschaft für Informatik (GI)
Open-Source Software
- Maintainer of BFT-SMaRt, a modern library for Byzantine fault-tolerant state machine replication
- Owner of Delphi-BFT, a tool for automating large-scale simulations of replication protocols
- Contributor to Mercury (Middleware 2024 artifact) and OptiLog, a BFT monitoring and optimization framework (EuroSys 2026 artifact)
Publications
See also my profiles on Google Scholar · dblp · ORCID.2026
Exploring Adaptive Byzantine Quorum Systems to Improve Latency in the WAN
Linus Gnan, Rüdiger Kapitza, Christian Berger
Latin-American Symposium on Dependable and Secure Computing (LADC 2026), to appear
Conference
HomeGuard: Community-Driven Hierarchical Federated Learning for Robust Smart-Home Intrusion Detection
Philipp Eichhammer, Christian Berger, Hans P. Reiser
23rd International Conference on Security and Cryptography (SECRYPT 2026), pp. 108–120, July 2026
Conference · DOI
OptiLog: Assigning Roles in Byzantine Consensus
Hanish Gogada, Christian Berger, Leander Jehl, Hans P. Reiser, Hein Meling
21st European Conference on Computer Systems (EuroSys 2026), pp. 1041–1061, April 2026
Conference · PDF · DOI · Code
2025
Optimized BFT Replication from Authenticated Logging
Hanish Gogada, Christian Berger, Leander Jehl, Hans P. Reiser, Hein Meling
ROBUST 2025 Workshop (Resilient Operations – Byzantine Fault Tolerance and State-Machine Replication), Karlsruhe, March 2025
Workshop · Abstract
2024
Chasing Lightspeed Consensus: Fast Wide-Area Byzantine Replication with Mercury
Christian Berger, Lívio Rodrigues, Hans P. Reiser, Vinícius Cogo, Alysson Bessani
25th ACM/IFIP International Middleware Conference (Middleware 2024), pp. 158–171, December 2024
Conference · Best Paper Runner-up · PDF · DOI · arXiv · Code · Talk (ConsensusDay 2023)
Exploring Scalability of BFT Blockchain Protocols through Network Simulations
Christian Berger, Sadok Ben Toumia, Hans P. Reiser
Formal Aspects of Computing, vol. 36, no. 4, pp. 1–29, ACM, December 2024
Journal · PDF · DOI
Towards Fast and Adaptive Byzantine State Machine Replication for Planetary-Scale Systems
Christian Berger
Doctoral thesis, Faculty of Computer Science and Mathematics, University of Passau, November 2024
PhD Thesis · Full text
Poster: Optimizing Tree-based Quorum Certification for BFT Systems at Planetary-Scale
Christian Berger, Hans P. Reiser
54th Annual IEEE/IFIP International Conference on Dependable Systems and Networks – Supplemental Volume (DSN-S 2024), pp. 154–156, June 2024
Poster · PDF · DOI
2023
Scalable Performance Evaluation of Byzantine Fault-Tolerant Systems Using Network Simulation
Christian Berger, Sadok Ben Toumia, Hans P. Reiser
28th IEEE Pacific Rim International Symposium on Dependable Computing (PRDC 2023), pp. 180–190, October 2023
Conference · PDF · DOI
SoK: Scalability Techniques for BFT Consensus
Christian Berger, Signe Schwarz-Rüsch, Arne Vogel, Kai Bleeke, Leander Jehl, Hans P. Reiser, Rüdiger Kapitza
5th IEEE International Conference on Blockchain and Cryptocurrency (ICBC 2023), pp. 1–18, May 2023
Conference · PDF · DOI
Skalierbare Performance-Simulation von fehlertoleranten verteilten Systemen
Christian Berger, Sadok Ben Toumia, Hans P. Reiser
Frühjahrstreffen der GI-Fachgruppen „Betriebssysteme“ (FGBS) und „Fehlertolerierende Rechensysteme“ (FERS), Dresden, March 2023
Talk · Abstract
2022
Does my BFT protocol implementation scale?
Christian Berger, Sadok Ben Toumia, Hans P. Reiser
3rd International Workshop on Distributed Infrastructure for the Common Good (DICG 2022), pp. 19–24, November 2022
Workshop · PDF · DOI · ResearchGate
Fast and Adaptive BFT State Machine Replication
Christian Berger
23rd International Middleware Conference Doctoral Symposium (Middleware 2022), pp. 7–10, November 2022
Doctoral Symposium · PDF · DOI
Automatic Integration of BFT State-Machine Replication into IoT Systems
Christian Berger, Hans P. Reiser, Franz J. Hauck, Florian Held, Jörg Domaschka
18th European Dependable Computing Conference (EDCC 2022), pp. 1–8, September 2022
Conference · Distinguished Paper Award · PDF · DOI · arXiv
An Evaluation of Blockchain Application Requirements and Their Satisfaction in Hyperledger Fabric: A Practical Experience Report
Sadok Ben Toumia, Christian Berger, Hans P. Reiser
22nd IFIP International Conference on Distributed Applications and Interoperable Systems (DAIS 2022), Springer LNCS, pp. 3–20, June 2022
Conference · DOI · arXiv
AWARE: Adaptive Wide-Area Replication for Fast and Resilient Byzantine Consensus
Christian Berger, Hans P. Reiser, João Sousa, Alysson Bessani
IEEE Transactions on Dependable and Secure Computing, vol. 19, no. 3, pp. 1605–1620, May 2022
Journal · PDF · DOI
2021
Making Reads in BFT State Machine Replication Fast, Linearizable, and Live
Christian Berger, Hans P. Reiser, Alysson Bessani
40th IEEE International Symposium on Reliable Distributed Systems (SRDS 2021), pp. 1–12, September 2021
Conference · Best Paper Award · PDF · DOI · arXiv · Video
A Survey on Resilience in the IoT: Taxonomy, Classification, and Discussion of Resilience Mechanisms
Christian Berger, Philipp Eichhammer, Hans P. Reiser, Jörg Domaschka, Franz J. Hauck, Gerhard Habiger
ACM Computing Surveys, vol. 54, no. 7, article 147, 39 pages, September 2021
Journal · PDF (Open Access) · DOI · Preprint
2020
Towards Environmental-Adaptive and Performance-Resilient Consensus in Distributed Ledger Technology
Christian Berger
21st International Middleware Conference Doctoral Symposium (Middleware 2020), pp. 1–4, December 2020
Doctoral Symposium · PDF · DOI · Video
2019
SORRIR: A Resilient Self-organizing Middleware for IoT Applications [Position Paper]
Jörg Domaschka, Christian Berger, Hans P. Reiser, Philipp Eichhammer, Frank Griesinger, Jakob Pietron, Matthias Tichy, Franz J. Hauck, Gerhard Habiger
6th International Workshop on Middleware and Applications for the Internet of Things (M4IoT 2019), co-located with Middleware 2019, pp. 13–16, December 2019
Workshop · PDF · DOI
Resilient Wide-Area Byzantine Consensus Using Adaptive Weighted Replication
Christian Berger, Hans P. Reiser, João Sousa, Alysson Bessani
38th IEEE International Symposium on Reliable Distributed Systems (SRDS 2019), October 2019
Conference · Best Paper Candidate · PDF · DOI · Poster · Slides · BibTeX
Towards a Robust, Self-Organizing IoT Platform for Secure and Dependable Service Execution
Philipp Eichhammer, Christian Berger, Hans P. Reiser, Jörg Domaschka, Franz J. Hauck, Gerhard Habiger, Frank Griesinger, Jakob Pietron
Tagungsband des FB-SYS Herbsttreffens 2019, Gesellschaft für Informatik e.V., 2019
Workshop · PDF · DOI
