What is symmetric cryptography?

In this IMFD talk, we will address the most common cryptographic primitives that underpin most of the protocols used in practice, with an emphasis on block ciphers. We will begin by exploring the Data Encryption Standard (DES), created by IBM under the influence of the NSA in the 1970s, the first widely standardized block cipher, reviewing its history and development process. We will then explain some notions of differential and linear cryptanalysis techniques, highlighting how they influenced the creation of Rijndael (AES), developed by Joan Daemen and Vincent Rijmen in 1998, whose structure and standardization process contrast with those of DES. Finally, we will discuss the common assumptions used to argue for the resilience of symmetric algorithms against differential attacks and the discrepancies between these assumptions and reality.