On Attacking Hash Functions in Cryptographic Schemes

Explore the intricacies of attacking hash functions in cryptographic schemes in this 43-minute lecture by Christian Majenz from the University of Amsterdam. Delve into the world of quantum cryptanalysis of post-quantum cryptography, covering topics such as the quantum random oracle model, domain extension, and the sponge construction. Examine hash functions in the NIST competition and learn various attack strategies. Investigate Sigma protocols, the Flat Shamir transformation, Fiat-Shamir signature scheme, and the Fujisaki Okamoto transformation. Gain insights into zero knowledge proofs and the uninstantiability of the QROM. Conclude with a comprehensive summary of the presented concepts and their implications for modern cryptography.

Intro
Hash functions...
Outline
Example application: Hash-and-sign
Quantum random oracle model
Domain extension
Example: the sponge construction
Hash functions in the NIST competition
How to attack hash functions?
Sigma protocols
Flat Shamir transformation
Fiat Shamir signature scheme
Fujisaki Okamoto transformation
Fiat-Shamir transformation in the GROM
Zero knowledge
The QROM is uninstantiable
Fujisaki-Okamoto transformation in the QROM
Summary