Together with Marco Timpanella (University of Perugia) and Giovanni Zini (University of Modena and Reggio Emilia), the research group organize monthly seminars.
23 October 2025 [5.00 pm - Italian time] - Pante Stanica (Naval Postegraduate School (Monterey) and Simion Stoilow Institute of Mathematics (IMAR) (Bucharest))
Title: An Extension of Differential Cryptanalysis on Modern Block Ciphers
Abstract: This talk introduces a novel extension of differential cryptanalysis, termed the "inner c-differential" attack, operating in finite fields of characteristic 2 (though, it easily extends to odd characteristic), which overcomes a key structural limitation that made prior generalizations impractical for real-world block ciphers. By moving the multiplicative constant c from the output to the input, our method ensures key cancellation, enabling multi-round analysis.
We apply this technique to the Russian standard cipher Kuznyechik (GOST R 34.12-2015). Using a rigorous statistical framework that includes False Discovery Rate (FDR) control and advanced anomaly detection metrics, we demonstrate the first practical statistical distinguisher against the full 9-round Kuznyechik cipher (variant without pre-whitening). The results show a verifiable, non-random behavior with high statistical confidence, suggesting that the security margin of some modern ciphers against this new attack vector may be insufficient.