Distribution and certification of photonic entanglement for quantum communication
E. Verbanis · Archive ouverte UNIGE (University of Geneva) · 2019
In this thesis, I study quantum resources for quantum communication and cryptography. The first part deals with bit commitment, a cryptographic primitive in which a party commits a secret bit to another party. After shortly presenting the security issues faced by quantum bit commitment, I demonstrate the first realization of a secure relativistic bit commitment sustained for 24 hours. The second part deals with the development of efficient methods to generate, distribute and characterize photonic entangled states. I address the problem of certifying entanglement in the presence of measurement imperfections, and demonstrate a practical implementation of a measurement-device-independent entanglement witness. I then address the challenge of long-distance distribution of entanglement. I demonstrate a heralded photon amplifier and entanglement swapping protocols adapted for the distribution of single photon entanglement, and further discuss the advantages and limitations of using single photon entanglement as a resource for quantum communication.