Loading...

Memory and Entanglement Assisted Secure Quantum Key Distribution

Fazelian, Masoume | 2017

507 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 50240 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Salehi, Jawad
  7. Abstract:
  8. Two major category of protocols suggested for quantum key distribution (QKD) are prepare and measure protocols and entanglement based protocols. One of the most challenging problem of these two categories is that they are not immune against attacks to measurement devices. For addressing this problem, measurement device independent protocol (MDI-QKD) was proposed in 2012; in which measurement device can be in hands of untrusted party. The idea of MDI-QKD is based on time-reversed EPR protocol. Still low secure key exchange rate has provoked many efforts, one of these efforts was to improve the key rate by means of quantum memories. In this thesis different proposed structures for memory assisted MDI-QKD has been compared. We develop a mathematical framework within which we can compare QKD systems with and without memories. Considering possible nonidealities in setup devices, required values of system parameters for appropriate performance and possible beating of no memory structure has been derived. In particular nonidealities in entangled photon pair source has been investigated and after careful analysis, the minimum required fidelity was obtained about 0.9. Since Coherence time-bandwidth product is crucial for system performance and it's challenging to have both high coherence time and bandwidth quantum memories, possible approach to have high repetition rate and sufficient coherence time with a slow memory has been compared and a good structure has been proposed
  9. Keywords:
  10. Quantum Memory ; Quantum Key Distribution ; Entanglement ; Quantum Key Distribution ; Key Rate

 Digital Object List

 Bookmark

No TOC