Section: New Results

Buidling blocks

Participant : Marine Minier.

In [17] , we develop a complete library of lightweight block ciphers dedicated to security applications in wireless sensor networks (WSNs). Choosing best algorithms in terms of energy-efficiency and of small memory requirements is a real challenge because the sensor networks must be autonomous. We study on a dedicated platform of sensors most of the recent lightweight block ciphers as well as some conventional block ciphers. First, we describe the design of the chosen block ciphers with a security summary and we then present some implementation tests performed on our platform. The library is available online: http://bloc.project.citi-lab.fr/library.html .

In [23] , we present two related key impossible differential attacks against 14 rounds of Piccolo-80 and 21 rounds of Piccolo-128 without the whitening layers. Piccolo is a new lightweight block cipher proposed by SONY at CHES 2011. The attack against Piccolo-80 has a time and data complexity of $2^{68.19}$ whereas the time/data complexity of the attack against Piccolo-128 is $2^{117.77}$.

While Generalized Feistel Networks have been widely studied in the literature as a building block of a block cipher, we propose in [13] a unified vision to easily represent them through a matrix representation. We then propose a new class of such schemes called Extended Generalized Feistel Networks well suited for cryptographic applications. We instantiate those proposals into two particular constructions and we finally analyze their security.

We also obtain, in [24] a result concerning an integral distinguisher on the SHA-3 finalist Grøstl-512 v3.