LI Xi-Han1,2, LI Chun-Yan1,2, DENG Fu-Guo1,2,3, ZHOU Ping1,2, LIANG Yu-Jie1,2, ZHOU Hong-Yu1,2,3
1The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875
2Institute of Low Energy Nuclear Physics, and Department of Material Science and Engineering, Beijing Normal University, Beijing 100875
3Beijing Radiation Center, Beijing 100875
Multiparty Quantum Remote Secret Conference
LI Xi-Han1,2;LI Chun-Yan1,2;DENG Fu-Guo1,2,3;ZHOU Ping1,2;LIANG Yu-Jie1,2; ZHOU Hong-Yu1,2,3
1The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875
2Institute of Low Energy Nuclear Physics, and Department of Material Science and Engineering, Beijing Normal University, Beijing 100875
3Beijing Radiation Center, Beijing 100875
Abstract： We present two schemes for multiparty quantum remote secret conference in which each legitimate conferee can read out securely the secret message announced by another, but a vicious eavesdropper can get nothing about it. The first one is based on the same key shared efficiently and securely by all the parties with reenberger--Horne--Zeilinger (GHZ) states, and each conferee sends his secret message to the others with one-time pad crypto-system. The other one is based on quantum encryption with a quantum key, a sequence of GHZ states shared among all the conferees and used repeatedly after confirming their security. Both these schemes are optimal as their intrinsic efficiency for qubits approaches the maximal value.
2007, Vol. 24 
