László Gyöngyösi, Sándor Imre
Quantum information theoretical based geometrical representation of eavesdropping activity on the quantum channel
Quantum information theoretical based geometrical representation of eavesdropping activity on the quantum channel
Keywords: quantum cryptography, quantum cloning, quantum informational distance
Quantum cryptography is an emerging technology that may offer new forms of security protection, however the quantum cloning based attacks against the protocol will play a crucial role in the future. According to the no-cloning theorem, an eavesdropper on the quantum channel can not copy perfectly the sent quantum states. In our method we use quantum relative entropy as an informational distance between quantum states. We show a geometrical approach to analyze the security of quantum cryptography, based on quantum relative entropy and Laguerre Delaunay triangulation on the Bloch sphere. We present a basically new method to derive quantum relative entropy based Delaunay tessellation on the Bloch ball and to compute the radius of smallest enclosing ball of balls to detect eavesdropping activity on the quantum channel.