Andy Rupp – Cryptographic Protocols Research

Research Interests

Cryptographic Protocols
Privacy-Enhancing Technologies
Provable Security
Anonymous Payments
Anonymous Communication
Lawful Interception

Current Appointments

Head, Research Group Cryptographic Protocols (CPRO), Uni.lu (since 01/23)
Principal Investigator, KASTEL Security Research Labs (since 01/21)
Spokesperson, KASTEL Research Group Secure Computation and Communication (since 01/21)
Co-Director, MSc in Cyber Security and Cyber Defence, Uni.lu (since 03/25)

Team

Current PhD Students: Chuanwei Lin (since 04/25), Andrey Bozhko (since 11/24), Dennis Faut (since 11/23)

Current PostDocs: Valerie Fetzer (since 12/24), Shalini Banerjee (since 05/24), Tapas Pal (since 02/24)

Former PhD Students: Valerie Fetzer (04/17-12/24), Michael Klooss (06/17-01/23)

In the Media

Innovative Sicherheitsprotokolle für die digitale Überwachung, Neuland Magazin 2024, 02/25.
Striking the balance in communication privacy and lawful interception, Uni.lu News, 07/19/24.
So könnten Cyberkriminelle legal gejagt werden, Wirtschaftwoche, 17/01/24.
Auditable Surveillance in Digital Monitoring, Helmholtz Blogs, 10/22/23.
Misuse-Resistant Digital Surveillance, KIT News, 10/12/23.
Wie sicher ist das Zahlen mit dem Handy?, Frankfurter Allgemeine Zeitung, Issue 08/22/18.
PriPay @ CEBIT 2018: Sichere und anonyme virtuelle Geldbörse, Youtube-Video, 7/2018.
"Ich weiß, was Du gestern gekauft hast.", Zeit-Online, 6/2018.
"Pfennig-Fuchser", Kaleidoskop der Wissenschaft — Linux Magazin, Issue 4/2018.
"Kryptologie", Resonator --- Der Forschungspodcast der Helmholtz-Gemeinschaft, Podcast, 2/2018.
"Anonym und sicher bezahlen", Fintech, Technology Review, 12/2017.
"Elektronische Geldbörse ohne Datenspur", Baden-TV, 10/2017.
"Verschlüsselte Spuren. Wie Kryptographie hilft, die digitale Privatsphäre zu schützen.", KIT-Podcast, 5/2017.
"Mehr Datenschutz beim Punktesammeln", ZDF-Heute Online-Magazine, 3/2017.
"Anonym sammeln: Ein neues Bonuskartensystem mit Kryptofunktion macht das Punktesammeln datenschutzfreundlich", Forschung Aktuell, Deutschlandfunk Radio, 3/2017.

Peer-Reviewed Publications

D. Faut, V. Fetzer, J. Müller-Quade, M. Raiber, A. Rupp. POBA: Privacy-Preserving Operator-Side Bookkeeping and Analytics. IACR Communications in Cryptology, Volume 2, Issue 2, 2025. [PDF]
D. Faut, J. Hesse, L. Kohl, and A. Rupp. Scalable and Fine-Tuned Privacy Pass from Group Verifiable Random Functions. Euro S&P 2025. [PDF]
T. Dai, Y. Jiang, Y. Li, J. Mueller-Quade, and A. Rupp. Honorific Security: Efficient Two Party Computation with Offloaded Arbitration and Public Verifiability. SECRYPT 2025.
A. Jolfei, S. Schiffner, T. Engel, and A. Rupp. Why Privacy-Preserving Protocols Are Sometimes Not Enough: A Case Study of the Brisbane Toll Collection Infrastructure. PETS 2024. [PDF]
V. Fetzer, M. Klooss, J. Mueller-Quade, M. Raiber, and A. Rupp. Universally Composable Auditable Surveillance. ASIACRYPT 2023. [PDF]
A. Jolfei, A. Boualouache, A. Rupp, S. Schiffner, and T. Engel. A Survey on Privacy-Preserving Electronic Toll Collection Schemes for Intelligent Transportation Systems. IEEE T-ITS 2023. [PDF]
V. Fetzer, M. Keller, S. Maier, M. Raiber, A. Rupp, and R. Schwerdt. C. Kuhn, D. Hofheinz, A. Rupp, and T. Strufe. PUBA: Privacy-Preserving User-Data Bookkeeping and Analytics. PETS 2022. [PDF]
C. Kuhn, D. Hofheinz, A. Rupp, and T. Strufe. Onion Routing with Replies. ASIACRYPT 2021. [PDF]
V. Fetzer, M. Hoffmann, M. Nagel, A. Rupp, and R. Schwerdt. P4TC: Provably-Secure yet Practical Privacy-Preserving Toll Collection. PETS 2020. [PDF]
M. Hoffmann, M. Klooss, M. Raiber, and A. Rupp. Black-Box Wallets: Fast Anonymous Two-Way Payments for Constrained Devices. PETS 2020. [PDF]
M. Hoffmann, M. Klooss, and A. Rupp. Efficient Zero-Knowledge Arguments in the Discrete Log Setting, Revisited. ACM CCS 2019. [PDF]
M. Klooss, A. Lehmann, and A. Rupp. (R)CCA Secure Updatable Encryption with Integrity Protection. EUROCRYPT 2019. [PDF]
V. Fetzer, T. Graef, M.Nagel, A. Rupp, and R. Schwerdt. P6V2G: A Privacy-Preserving V2G Scheme for Two-Way Payments and Reputation. DACH+ 2019. [PDF]
B. Broadnax, V. Fetzer, J. Mueller-Quade, and A. Rupp. Non-Malleability vs. CCA-Security: The Case of Commitments. PKC 2018. [PDF]
G. Hartung, M. Hoffmann, M. Nagel, and A. Rupp. BBA+: Improving the Security and Applicability of Privacy-Preserving Point Collection. ACM CCS 2017. [PDF]
G. Herold, M. Hoffmann, M. Klooss, C. Rafols, and A. Rupp. New Techniques for Structural Batch Verification in Bilinear Groups with Applications to Groth-Sahai Proofs. ACM CCS 2017. [PDF]
D. Hofheinz, T. Jager and A. Rupp. Public-Key Encryption with Simulation-Based Selective-Opening Security and Compact Ciphertexts. TCC 2016. [PDF]
T. Jager and A. Rupp. Black-Box Accumulation: Collecting Incentives in a Privacy-Preserving Way. PETS 2016. [PDF]
G. Hartung, B. Kaidel, A. Koch, J. Koch, A. Rupp. Fault-Tolerant Aggregate Signatures. PKC 2016. [PDF]
J. Hesse, D. Hofheinz, and A. Rupp. Reconfigurable Cryptography: A Flexible Approach to Long-Term Security. TCC 2016. [PDF]
A. Rupp, F. Baldimitsi, G. Hinterwalder, and C. Paar. Cryptographic Theory Meets Practice: Efficient and Privacy-Preserving Payments for Public Transport. ACM TISSEC. [PDF]
G. Herold, J. Hesse, D. Hofheinz, R. Rafols, and A. Rupp. Polynomial Spaces: A New Framework for Composite-To-Prime-Order Transformations. CRYPTO 2014. [PDF]
D. Hofheinz and A. Rupp. Standard versus Selective Opening Security: Separation and Equivalence Results. TCC 2014. [PDF]
A. Rupp, F. Baldimitsi, G. Hinterwalder, and C. Paar. P4R: Privacy-Preserving Pre-Payments with Refunds for Transportation Systems. FC 2013. [PDF]
M. Keller, G. L. Mikkelsen, and A. Rupp. Threshold Zero-Knowledge with Applications to User-Centric Cryptographic Protocols. ICITS 2012. [PDF]
F. Baldimtsi, G. Hinterwalder, A. Rupp, A. Lysyanskaya, C. Paar, and W. P. Burleson. Pay As You Go. HotPETs 2012. [PDF]
T. Jager and A. Rupp. The Semi-Generic Group Model and Applications to Pairing- Based Cryptography. ASIACRYPT 2010. [PDF]
A. Rupp, T. Eisenbarth, A. Bogdanov, and O. Grieb. Hardware SLE Solvers: Efficient Building Blocks for Cryptographic and Cryptanalytic Applications. Elsevier Integration, the VLSI Journal - Special Issue “Hardware Architectures for Algebra, Cryptology and Number Theory”, 2010. [PDF]
C. Paar, A. Rupp, K. Schramm, A. Weimerskirch, and W. Burleson. Securing Green Cars: IT Security in Next-Generation Electric Vehicle Systems. ITS America's 2009 Annual Meeting & Exposition. [PDF]
C. Paar, J. Pelzl, A. Rupp, K. Schramm, and A. Weimerskirch. Green Car Security: IT-Sicherheit und Elektromobilität. DACH Security 2009. [PDF]
T. Güneysu, T. Kasper, M. Novotny, C. Paar, and A. Rupp. Cryptanalysis with COPACOBANA. IEEE Transactions on Computers 2008. [PDF]
A. Rupp, G. Leander, E. Bangerter, A. Dent, and A. Sadeghi. Sufficient Conditions for Intractability over Black-Box Groups: Generic Lower Bounds for Generalized DL and DH Problems. ASIACRYPT 2008. [PDF]
K. Altmann, T. Jager, and A. Rupp. On Black-Box Ring Extraction and Integer Factorization. ICALP 2008. [PDF]
B. Möller and A. Rupp. Faster Multi-Exponentiation through Caching: Accelerating (EC)DSA Signature Verification. SCN 2008. [PDF]
A. Bogdanov, T. Eisenbarth, A. Rupp, and C. Wolf. Time-Area Optimized Public-Key Engines: MQ-Cryptosystems as Replacement for Elliptic Curves?. CHES 2008 (Best Paper Award). [PDF]
T. Gendrullis, M. Novotny, and A. Rupp. A Real-World Attack Breaking A5/1 within Hours. CHES 2008. [PDF]
S. Balasubramanian, A. Bogdanov, A. Rupp, J. Ding, and H. W. Carter. Fast Multivariate Signature Generation in Hardware: The Case of Rainbow. IEEE ASAP 2008. [PDF]
S. Balasubramanian, A. Bogdanov, A. Rupp, J. Ding, and H. W. Carter. Fast Multivariate Signature Generation in Hardware: The Case of Rainbow (short paper). IEEE FCCM 2008. [PDF]
A. Bogdanov, T. Eisenbarth, and A. Rupp. A Hardware-Assisted Realtime Attack on A5/2 without Precomputations. CHES 2007. [PS]
T. Güneysu, A. Rupp, and S. Spitz. Cryptanalytic Time-Memory Tradeoffs on COPACOBANA. GI Informatik 2007 Workshop Kryptologie in Theorie und Praxis (German). [PDF]
G. Leander and A. Rupp. On the Equivalence of RSA and Factoring Regarding Generic Ring Algorithms. ASIACRYPT 2006. [PDF]
A. Bogdanov, M. Mertens, C. Paar, J. Pelzl, and A. Rupp. A Parallel Hardware Architecture for fast Gaussian Elimination over GF(2). IEEE FCCM 2006. [PDF]
S. Kumar, C. Paar, J. Pelzl, G. Pfeiffer, A. Rupp, and M. Schimmler. How to break DES for EUR 8,980. SHARCS 2006. [PDF]
A. Bogdanov, M. Mertens, C. Paar, J. Pelzl, and A. Rupp. SMITH - a Parallel Hardware Architecture for fast Gaussian Elimination over GF(2). SHARCS 2006. [PDF]
E. Bangerter, A. Rupp, and A. Sadeghi. Simplified Hardness Proofs in the Generic Group Model. WEWoRC 2005. [PDF]
A. Rupp, H. Dreger, A. Feldmann, and R. Sommer. Packet Trace Manipulation Framework for Test Labs. ACM IMC 2004. [PDF]

Dr. Andy Rupp

Research Interests

Current Appointments

Team

In the Media

Peer-Reviewed Publications

Committees