Stefan Kölbl

Information Security Engineer

Google

Biography

I am a cryptographer working at Google in the information security engineering team. Before, I have been the Senior Technology Manager at Cybercrypt.

After I obtained my PhD degree, I have been a postdoctoral researcher in the Cyber Security group at the Technical University of Denmark working on the H2020 PQCRYPTO project. I did my PhD under the supervision of gate io and Lars Knudsen at DTU Compute, Technical University of Denmark, working on the design and analysis of symmetric key cryptographic algorithms.

Interests

  • Post-quantum Cryptography
  • Cryptographic Hash Functions and Block Ciphers
  • Secure and Efficient Implementations
  • Tools for Cryptanalysis

Education

  • PhD in Cryptology, 2016

    Technical University of Denmark

  • MSc in Computer Science, 2013

    Graz University of Technology

  • BSc in Computer Science, 2011

    Graz University of Technology

Services

Program Committee

Conference Refereeing

  • 2022: Crypto, FSE
  • 2021: FSE, PQCrypto
  • 2020: CHES, FSE
  • 2019: FSE, Latincrypt, PQCrypto
  • 2018: Asiacrypt, Designs, Codes and Cryptography, FSE, IET Information Security, Transactions on Computers, The Computer Journal, PQCrypto
  • 2017: Africacrypt, FSE, IET Information Security, PQCrypto
  • 2016: ACNS, Crypto, FSE, IET Information Security, Journal of Cryptographic Engineering
  • 2015: Asiacrypt, Eurocrypt, FSE, IET Information Security, Indocrypt, CT-RSA, SAC, ISISC
  • 2014: ACNS, Asiacrypt, CANS, FSE

Standardization

Representative of Switzerland for ISO/IEC JTC 1 SC 27 (IT Security techniques) Work Group 2 (Cryptography and security mechanisms) from 2020 to now.

Representative of Denmark for ISO/IEC JTC 1 SC 27 (IT Security techniques) Work Group 2 (Cryptography and security mechanisms) from 2017 to 2019.

Projects

CryptoSMT

A tool for automating differential cryptanalysis for cryptographic primitives.

Gimli

A cryptographic permutation designed for high performance. Gimli is part of the NIST Lightweight Project and is part of LibHydrogen.

Haraka

A short-input hash function optimized for high performance on platforms supporting AES-NI. Used in SPHINCS+ and Gravity-SPHINCS.

Pyjamask

A cipher designed for efficient software implementations with strong side-channel protections submitted to the NIST Lightweight Project …

Skinny

A lightweight tweakable block cipher with strong security guarantees. Submitted to the NIST Lightweight Project.

SPHINCS+

A digital signature scheme submitted to the NIST Post-Quantum Project.

Talks

ShiftRows Alternatives for AES-like Ciphers and Optimal Cell Permutations for Midori and Skinny
Mar 2019 FSE 2019 Paris
Post-quantum Cryptography
May 2018 Dansk Standard Copenhagen
Update on the PQCrypto Project
Apr 2018 ISO/IEC JTC1 SC27 Wuhan
Putting Wings on SPHINCS
Apr 2018 PQCrypto 2018 Fort Lauderdale, FL
How to instantiate Hash-based Signatures?
Jan 2018 Combined event on Post-Quantum Cryptography Tenerife
See all talks

Contact