11/8/2017

By **Óscar Pereira**, HASLab, INESC TEC & Minho University.

**Abstract**. We explore the possibility of modelling a working block cipher, and analysing its security, exclusively through an algebraic framework of polynomial rings and finite fields: one aims to get the simplest formal models of ciphers for which it is possible to get demonstrative evidence of its security but still with reasonably efficient implementations.

**Keywords**. Security, Cryptography, Symmetric ciphers.

**About the Speaker**. Óscar Pereira is currently a PhD candidate at MAP-I and a researcher at HASLab, INESC TEC, Braga. Having completed his masters at UMinho on the subject "Towards a fully algebrisable Symmetric Cryptosystem", in 2015, his PhD thesis can be seen as a continuation of that work, which is supervised by Prof. José Manuel Valença. In particular, Óscar's focus is on how to leverage the algebraic descriptions of cryptographic primitives in order to improve the way one reasons about their security. Prior to his graduate studies, Óscar has also spent some time in the industry working on web development and AI; but he felt missing mathematics and decided to dive deep in the pool, focusing on cryptography.

**Address: **University of Minho, Gualtar campus, Braga, Portugal.

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