Finding Integral Distinguishers with Ease

Aug 1, 2018·
Zahra Eskandari
,
Andreas Brasen Kidmose
Stefan Kölbl
Stefan Kölbl
,
Tyge Tiessen
· 0 min read
Abstract
The division property method is a technique to determine integral distinguishers on block ciphers. While the complexity of finding these distinguishers is higher, it has recently been shown that MILP and SAT solvers can efficiently find such distinguishers. In this paper, we provide a framework to automatically find those distinguishers which solely requires a description of the cryptographic primitive. We demonstrate that by finding integral distinguishers for 30 primitives with different design strategies. We provide several new or improved bit-based division property distinguishers for ChaCha, Chaskey, DES, GIFT, LBlock, Mantis, Qarma, RoadRunner, Salsa and SM4. Furthermore, we present an algorithm to find distinguishers with lower data complexity more efficiently.
Type
Publication
publications
Stefan Kölbl
Authors
Staff Engineer, Tech Lead Manager

I am a Staff Engineer and Tech Lead Manager at Google, where I work in the Security Engineering team. My focus is on post-quantum cryptography and enabling developers at Google and across the internet to use cryptography safely and correctly.

I have a PhD in cryptography and an extensive background in the design and analysis of symmetric-key algorithms, post-quantum cryptography, and lightweight cryptography. I have contributed to several cryptographic standardization efforts, including the SKINNY cipher, which is part of the ISO/IEC 29192-2 standard. I also contributed to the SPHINCS+ signature scheme, which was standardized by NIST as FIPS 205. I currently represent Switzerland in the ISO/IEC JTC 1/SC 27/WG 2 committee for cryptography and security mechanisms.

Before joining Google, I was a Senior Technology Manager at Cybercrypt and a postdoctoral researcher at the Technical University of Denmark, working on the H2020 PQCRYPTO project.