Sabine Oechsner

I am a Postdoc in the Cryptography and Security group at Aarhus University, Denmark, hosted by Jesper Buus Nielsen. Previously, I was a PhD student in the Cryptography and Security group at Aarhus University under the supervision of Ivan Damgård. I hold an M.Sc. in Computer Science from Karlsruhe Institute of Technology, Germany.

In Fall 2017, I was a long-term visitor at NTT Secure Platform Laboratories, and in Spring 2018 at IDC Herzliya, visiting Elette Boyle.

News

• I'm on the PC of CSF 2022!
• "TARDIS: A Foundation of Time-Lock Puzzles in UC" with Carsten Baum, Bernardo David, Rafael Dowsley and Jesper Buus Nielsen got accepted to Eurocrypt 2021.

Research

I study cryptography and its intersection with formal methods. I am particularly interested in making the two worlds meet in what I believe is the right way: Instead of merely reproducing existing cryptographic proofs with tool support, my goal is to use formal verification as an opportunity to understand how to write better proofs with high assurance, both on paper and in a machine-checkable way. My current focus is on secure computation and similar protocols. I also study the security of secure computation protocols in general.
During my PhD, I worked on the design of efficient privacy-preserving cryptographic primitives, in particular zero-knowledge proofs and ring signatures.

Pre-Prints

• Formal security analysis of MPC-in-the-head zero-knowledge protocols
  with Nikolai Sidorenco and Bas Spitters
  [eprint]
• Bringing State-Separating Proofs to EasyCrypt - A Security Proof for Cryptobox
  with François Dupressoir and Konrad Kohbrok
  [eprint]
• CRAFT: Composable Randomness and Almost Fairness from Time
  with Carsten Baum, Bernardo David, Rafael Dowsley, and Jesper Buus Nielsen
  [eprint]

Publications

• TARDIS: A Foundation of Time-Lock Puzzles in UC
  with Carsten Baum, Bernardo David, Rafael Dowsley, and Jesper Buus Nielsen
  Eurocrypt 2021
  [eprint]
• Adaptive Security of Practical Garbling Schemes
  with Zahra Jafargholi
  Indocrypt 2020
  [eprint] [video]
• Towards Practical Lattice-Based One-Time Linkable Ring Signatures
  with Carsten Baum and Huang Lin
  ICICS 2018
  [eprint]
• More Efficient Commitments from Structured Lattice Assumptions
  with Carsten Baum, Ivan Damgård, Vadim Lyubashevsky, and Chris Peikert
  SCN 2018
  [eprint]
• Computer-Aided Proofs for Multiparty Computation with Active Security
  with Helene Haagh, Aleksandr Karbyshev, Bas Spitters, and Pierre-Yves Strub
  CSF 2018
  [eprint]
• Compact Zero-Knowledge Proofs of Small Hamming Weight
  with Ivan Damgård, Ji Luo, Peter Scholl, and Mark Simkin
  PKC 2018
  [eprint] [slides]

Selected Talks

• Modelling security - A cryptographer's view of the world
  Logic and Semantics group, Aarhus University, December 2, 2019
• On Simulation-Based Security Proofs with State Separation
  IT-University Copenhagen, November 5, 2019
• Exploring State-Separating Proofs for Multi-Party Computation
  TPMPC 2019, Tel Aviv, June 17-20, 2019
• Computer-Aided Proofs for Multiparty Computation with Active Security
  DIMACS/MACS Workshop on Usable, Efficient, and Formally Verified Secure Computation, Boston, March 14-15, 2019
  [video]
• Computer-Aided Proofs for Multiparty Computation with Active Security
  TPMPC 2018, Aarhus, May 28-31, 2018
  [video]
• Towards a Proof of Active Security for Multiparty Computation in EasyCrypt
  PhD Course on Computer-Aided Security Proofs, Aarhus, October 9-13, 2017

Service

I serve(d) on the program committee of the following conferences:

• CSF 2022, 2021
• Indocrypt 2020

Aarhus Crypto Seminar

In 2019 and 2020, I organized the weekly seminar of the Cryptography group at Aarhus University. Here is the list of talks during that time.

Contact

Department of Computer Science
Aarhus University
Åbogade 34
8200 Aarhus N
Denmark

Office: Nygaard-280 (map)
Email: lastname at cs.au.dk

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How to pronounce my last name

The combination OE is an old spelling of the German letter Ö. The pronounciation is similar to the Scandinavian Ø or the French Œ, or the vowel in the English word learn. If you are in doubt, use O instead. The CHS in the middle of my name is pronounced like X or KS in English.