Soutenance de thèse de Phuong Hoa Nguyen (équipe CAPSULE) : "New Automated Approaches in Cryptanalysis"

Abstract:

Traditional cryptanalysis often relies on heuristic and statistical methods, but automated tools have recently gained significant attention. This thesis explores their application to improve cryptanalysis for specific ciphers.

We first revisit related-key boomerang attacks on AES, introducing an advanced MILP model to handle its nonlinear key schedule, significantly reducing the time complexity compared to previous approaches. Next, we enhance the rebound attack on the Grøstl hash function using a unified MILP model that automates the search for differential paths in both the inbound and outbound phases. Finally, we extend the differential meet-in-the-middle (MITM) framework from word-oriented to bit-oriented AndRX ciphers, proposing the first automated bit-wise model capable of identifying complete differential MITM attacks for these ciphers. 

The results presented in this thesis demonstrate the potential of automated tools in cryptanalysis, offering new insights into the security of modern block ciphers and hash functions.
 

I look forward to seeing you there!