Subspace based encryption: concepts and robustness study = Chiffrement basé sur les méthodes sous-espace: concepts et étude de robustesse

Abstract

In this thesis, a new subspace-based encryption system is proposed to bypass the weaknesses, from a security point of view, of the encryption schemes based on blind source separation techniques. Orthogonal and oblique subspace-based encryption schemes, both simple and iterative, are designed and analyzed in terms of security robustness and quality of recovered signals. Security analysis is conducted using cryptanalysis attacks whereas quality assessment is achieved using both objective and subjective tools. The proposed subspacebased encryption system is applied for speech, image and data. Experimental results show an enhancement in the performances beside some interesting and specific features, from a cryptographic point of view, brought by the proposed encryption system.