A Cryptographic Approach to Preventing Unauthorized Access

Defense type
Thesis
Starting date
End date
Location
IRISA Rennes
Room
MARKOV
Speaker
Adina NEDELCU
Main department
Theme

Communication through digital means is playing an increasingly important role in our lives. As the exchanged data can often be sensitive or private, special care must be taken to prevent it from being accessed by unauthorized parties. In this thesis, we analyse this problem in several contexts and propose a series of solutions.
We first consider mobile phone networks, where compatibility with lawful interception requests is an immutable constraint. We propose a new primitive called Lawful Interception Key Exchange, or LIKE. LIKE allows for secure channel establishment and increased privacy, while still being lawful interception compliant.
Next, we investigate the privacy of the Transport Layer Protocol version 1.3 (TLS), widely used for secure channel establishment over the internet. We propose a model for privacy and show that TLS 1.3 is privacy-preserving in our model.
Finally, we analyse deep attestation protocols, with a focus on the property of linking. We propose a formal, cryptographic approach to this topic, as well as a new construction.

Composition of the jury
- Gildas AVOINE Professeur, INSA Rennes
- Sébastien GAMBS Professeur, UQUAM, Rapporteur
- Patrick LACHARME Maître de conférence, ENSICAEN, Rapporteur
- Maryline LAURENT Professeur, Telecom SudPari, Examinateur
- Cristina ONETE Maître de conférence, IUT Limoges, Examinatrice
- Ghada ARFAOUI Ingénieur, Orange Labs, Rennes, Examinateur
- Pierre-Alain FOUQUE Professeur, Université de Rennes 1, Directeur de thèse