Sebastian Ramacher

I am a researcher in cryptography and PhD student at IAIK, Graz University of Technology. My main research interests are in the field of public key cryptography with a focus on post-quantum signature schemes and modern public key cryptography.

Publications and Talks

Conferences and Journals

2018 David Derler, Sebastian Ramacher, Daniel Slamanig. Generic Double-Authentication Preventing Signatures and a Post-Quantum Instantiation ProvSec 2018
2018 David Derler, Sebastian Ramacher, Daniel Slamanig. Post-Quantum Zero-Knowledge Proofs for Accumulators with Applications to Ring Signatures from Symmetric-Key Primitives. PQCrypto 2018
2018 David Derler, Stephan Krenn, Thomas Lorünser, Sebastian Ramacher, Daniel Slamanig, Christoph Striecks: Revisiting Proxy Re-Encryption: Forward Secrecy, Improved Security and Applications. PKC 2018
2018 David Derler, Sebastian Ramacher, Danial Slamanig. Short Double- and N-Times-Authentication-Preventing Signatures from ECDSA and More. Euro S&P 2018
2017 Melissa Chase, David Derler, Steven Goldfeder Claudio Orlandi, Sebastian Ramacher, Christian Rechberger, Daniel Slamanig, Greg Zaverucha. Post-Quantum Zero-Knowledge and Signatures from Symmetric-Key Primitives. CCS 2017
2017 David Derler, Sebastian Ramacher, Daniel Slamanig. Homomorphic Proxy Re-Authenticators and Applications to Verifiable Multi-User Data Aggregation. FC 2017.
2015 Alfred Geroldinger, Sebastian Ramacher, Andreas Reinhart. On v-Marot Mori rings and C-rings. Journal of the Korean Mathematical Society Vol. 52 No. 1/2015

Preprints

2017 Léo Perrin, Angela Promitzer, Sebastian Ramacher, Christian Rechberger. Improvements to the Linear Layer of LowMC: A Faster Picnic
2016 David Derler, Claudio Orlandi, Sebastian Ramacher, Christian Rechberger, Daniel Slamanig. Digital Signatures from Symmetric-Key Primitives

Talks

2018 Generic Double-Authentication Preventing Signatures and a Post-Quantum Instantiation at ProvSec 2018..
2018 Post-Quantum Zero-Knowledge Proofs for Accumulators with Applications to Ring Signatures from Symmetric-Key Primitives at PQCrypto 2018.
2018 Short Double- and N-Times-Authentication-Preventing Signatures from ECDSA and More at Euro S&P 2018.
2017 Post-Quantum Zero-Knowledge and Signatures from Symmetric-Key Primitives at CCS 2017 on November 2, 2017 (together with Steven Goldfeder).
2017 Post-Quantum Zero-Knowledge and Signatures from Symmetric-Key Primitives at Microsoft Research on October 26, 2017.
2017 Post-Quantum Zero-Knowledge and Signatures from Symmetric-Key Primitives at CryptoSymposium 2017 on March 28, 2017.

NIST PQC Competition: Picnic

The Picnic family of digital signature algorithms is designed to provide security against attacks by quantum computers, in addition to attacks by classical computers. The building blocks are a zero-knowledge proof system (with post-quantum security), and symmetric key primitives like hash functions and block ciphers, with well-understood post-quantum security. An implementation optimized for speed is available on GitHub. Packages for Ubuntu bionic and cosmic are available as PPA.

Projects

Other Activities

Reviewer for International Conferences

Eurocrypt 2019, ACNS 2018, APKC 2018, CT-RSA 2018, ICDCS 2018, Asiacrypt 2017, SECPID 2017, Eurocrypt 2017, Africacrypt 2016, ICISC 2016

Teaching

I am currently involved with the following courses:

Potential topics for student projects, bachelor’s and master’s thesis can be found here:

Contact information