Télécom ParisTech


PhD defense Katarzyna Kapusta : Protecting data confidentiality combining data fragmentation, encryption, and dispersal over a distributed environment


PhD Comics : I'm defending my thesis, Mom !


  • Mr. Frédéric Cuppens - Reviewer   - Professor - Télécom Bretagne
  • Mr. Roberto di Pietro – Reviewer – Professor -  Hamad Bin Khalifa University
  • Mr. Louis Goubin – Reviewer –Professor - University of Versailles-St-Quentin-en-Yvelines
  • Ms. Samia Bouzefrane – Examiner – Associate Professor - Conservatoire National des Arts et Métiers
  • Ms. Nora Cuppens – Examiner – Research Director – Télécom Bretagne
  • Mr. Artur Janicki – Examiner - Maître de Conférences - Warsaw University of Technology
  • Mr. Jean Leneutre – Examiner - Associate Professor - Télécom ParisTech  
  • Mr. Gérard Memmi – Supervisor – Professor – Télécom ParisTech


Data protection using a combination of data encryption, fragmentation, and dispersal is revisited in the context of distributed storage. First, the family of all-or-nothing transforms is extended with three new proposals protecting outsourced data against the exposure of the encryption key.  Second, two ways of accelerating data fragmentation are introduced. They achieve better performance than the most common symmetric-key encryption algorithm. Finally, an additively homomorphic scheme for distributed storage inside Unattended Wireless Sensor Networks is introduced. It reduces by at least half the storage and transmission costs in comparison to the state-of-the art techniques.