【Abstract】Quantum secure direct communication (QSDC) is one branch of quantum cryptography. In QSDC, secret message is sent directly over a quantum channel securely. This is possible due to the use of block data transmission technique. QSDC offers higher security in transmission. The information is transmitted instantaneously in the quantum channel in QSDC. In addition to security in transmission, QSDC also provides user site security.  QSDC is also a powerful basic quantum communication primitive to build other quantum communication protocols such as quantum bidding, quantum signature and quantum dialogue and so on. In this talk, I will briefly introduce the basic ideas of QSDC, some typical QSDC protocols, QSDC in a noisy and lossy environment, experimental development of QSDC. In particular, I will emphasize that QSDC is well within the current technology. Future perspective is also given toward the end of the talk.

Work supported by China National Natural Science Foundation, the Ministry of Science and Technology of China.

【个人简介】龙桂鲁教授，英国和美国物理学会会士，国家杰出青年基金获得者。获国家自然科学二等奖，教育部自然科学一等奖等。2016年当选担任亚太物理联合会理事长。1982年获得山东大学理学学士，1987年分别获得清华大学理学博士学位。1987年开始在清华大学任教至今。1989-1993年在英国萨塞克斯大学从事博士后研究。

主要学术贡献：建立和发展了量子直接通信，使之成为量子通信的重要方向；提出量子搜索相位匹配理论，构造迄今最简单的优化量子精确搜索算法，被称为Grover-Long算法。发表论文200余篇，被引13000多次。