ZUCCA Vincent

PhD graduated
Departure date : 12/25/2018

Supervision : Jean-Claude BAJARD

Towards Efficient Arithmetic for Ring-LWE based Homomorphic Encryption

Fully homomorphic encryption is a kind of encryption offering the ability to manipulate encrypted data directly through their ciphertexts. In this way it is possible to process sensitive data without having to decrypt them beforehand, ensuring therefore the datas' confidentiality. At the numeric and cloud computing era this kind of encryption has the potential to considerably enhance privacy protection. However, because of its recent discovery by Gentry in 2009, we do not have enough hindsight about it yet. Therefore several uncertainties remain, in particular concerning its security and efficiency in practice, and should be clarified before an eventual widespread use.
This thesis deals with this issue and focus on performance enhancement of this kind of encryption in practice. In this perspective we have been interested in the optimization of the arithmetic used by these schemes, either the arithmetic underlying the Ring Learning With Errors problem on which the security of these schemes is based on, or the arithmetic specific to the computations required by the procedures of some of these schemes. We have also considered the optimization of the computations required by some specific applications of homomorphic encryption, and in particular for the classification of private data, and we propose methods and innovative technics in order to perform these computations efficiently. We illustrate the efficiency of our different methods through different software implementations and comparisons to the related art.

Defence : 06/25/2018

Jury members :

M. Fabien Laguillaumie, Professeur, Université de Lyon [rapporteur]
M. Frederik Vercauteren, Associate Professor, KU Leuven [rapporteur]
M. Jean-Claude Bajard, Professeur Sorbonne Université
Mme. Anne Canteaut, Directrice de recherche, INRIA Paris
M. Léo Ducas, Researcher, CWI Amsterdam
M. Philippe Elbaz-Vincent, Professeur, Université Grenoble Alpes
Mme. Caroline Fontaine, Chargée de recherche, CNRS
Mme. Adeline Roux-Langlois, Chargée de recherche, CNRS

Departure date : 12/25/2018

2016-2019 Publications