I am a PhD candidate at the
Institute of Science and Technology Austria (ISTA) in the
Cryptography group supervised by
Krzysztof Pietrzak. My research is mostly concerned with the use of physical resources (e.g., disk space) in cryptography. Covering both theory and practice, my works range from memory-complexity lowerbounds for
trapdoor memory-hard functions to using proofs of space as a sybil-resistance mechanism for distributed hash tables.
Before joining ISTA, I completed the
Bachelor with Honors program at
TU Wien under the mentorship of
Matteo Maffei. During undergrad, I also participated in CTFs playing with the team
We_0wn_Y0u.
My email address is
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Publications
Putting Sybils on a Diet: Securing Distributed Hash Tables using Proofs of Space
Christoph U. Günther, Krzysztof Pietrzak
In submission
To appear: Workshop on Cryptographic Tools for Blockchains @ Eurocrypt 2025 (non-archival)
Full version
In submission
To appear: Workshop on Cryptographic Tools for Blockchains @ Eurocrypt 2025 (non-archival)
Full version
Nakamoto Consensus from Multiple Resources
Mirza Ahad Baig, Christoph U. Günther, Krzysztof Pietrzak
In submission
To appear: Workshop on Cryptographic Tools for Blockchains @ Eurocrypt 2025 (non-archival)
Full version
In submission
To appear: Workshop on Cryptographic Tools for Blockchains @ Eurocrypt 2025 (non-archival)
Full version
Constrained Verifiable Random Functions Without Obfuscation and Friends
Nicholas Brandt, Miguel Cueto Noval, Christoph U. Günther, Akin Ünal, Stella Wohnig
In submission
In submission
Deniability in Automated Contact Tracing: Impossibilities and Possibilities
Christoph U. Günther, Krzysztof Pietrzak
Privacy Enhancing Technologies Symposium 2024
Full version · DOI · Talk · Slides
Privacy Enhancing Technologies Symposium 2024
Full version · DOI · Talk · Slides
Trapdoor Memory-Hard Functions
Benedikt Auerbach, Christoph U. Günther, Krzysztof Pietrzak
Eurocrypt 2024
Full version · DOI · Talk · Slides
Eurocrypt 2024
Full version · DOI · Talk · Slides
Practical Asynchronous Proactive Secret Sharing and Key Refresh
Christoph U. Günther*, Sourav Das, Lefteris Kokoris-Kogias
Cryptology ePrint Archive 2022
Full version · Code
Cryptology ePrint Archive 2022
Full version · Code