Eavesdropping on the “Ping-Pong” Quantum Communication Protocol
Eavesdropping on the “Ping-Pong” Quantum Communication Protocol
Security of the "ping-pong" quantum communication protocol recently proposed by Boström and Felbinger [Phys. Rev. Lett. 89, 187902 (2002)]] is analyzed in the case of considerable quantum channel losses. The eavesdropping scheme is presented, which reveals that the ping-pong protocol is not secure for transmission efficiencies lower than 60%. Our …