Quantum key distribution protocols with and without rotational

          @misc{ pirsa_PIRSA:06110040,
            doi = {10.48660/06110040},
            url = {https://pirsa.org/06110040},
            author = {},
            keywords = {Quantum Information},
            language = {en},
            title = {Quantum key distribution protocols with and without rotational },
            publisher = {Perimeter Institute},
            year = {2006},
            month = {nov},
            note = {PIRSA:06110040 see, \url{https://pirsa.org}}
          }
          

Abstract

We explore the role of rotational symmetry of quantum key distribution (QKD) protocols in their security. Specifically, in the first part of the talk, we consider a generalized QKD protocol with discrete rotational symmetry. Note that, before our work, each QKD protocol seems to have a different security proof. Given that the techniques of those proofs are similar, it will be interesting to have a unified proof for QKD protocols with symmetry (e.g., the BB84 protocol and the SARG04 protocol). This is exactly what we achieve in our work. We show that rotational symmetry plays an important role in the unified security proof of QKD protocols with symmetry, leading to simple and structural security relations. In the second part, we consider a QKD protocol that does not possess rotational symmetry and analyze its security. Interestingly, even without any rotational symmetry, this protocol can still be proven secure. However, the security relation is not as simple as those in the first part, due to the lack of symmetry. Therefore, although rotational symmetry is not required in a QKD protocol to ensure its security, rotational symmetry does provide significant simplification in the security analysis, leading to simple security relations.