Experiments of 10 Gbit/sec quantum stream cipher applicable to optical Ethernet and optical satellite link

Abstract

The security issue for the next generation optical network which realizes Cloud Computing System Service with data center" is urgent problem. In such a network, the encryption by physical layer which provide super security and small delay should be employed. It must provide, however, very high speed encryption because the basic link is operated at 2.5 Gbit/sec or 10 Gbit/sec. The quantum stream cipher by Yuen-2000 protocol (Y-00) is a completely new type random cipher so called Gauss-Yuen random cipher, which can break the Shannon limit for the symmetric key cipher. We develop such a cipher which has good balance of the security, speed and cost performance. In SPIE conference on quantum communication and quantum imaging V, we reported a demonstration of 2.5 Gbit/sec system for the commercial link and proposed how to improve it to 10 Gbit/sec. This paper reports a demonstration of the Y-00 cipher system which works at 10 Gbit/sec. A transmission test in a laboratory is tried to get the basic data on what parameters are important to operate in the real commercial networks. In addition, we give some theoretical results on the security. It is clarified that the necessary condition to break the Shannon limit requires indeed the quantum phenomenon, and that the full information theoretically secure system is available in the satellite link application.

Quantum key distribution by phase flipping of coherent states of light

“…, which for two quasi-orthogonal states from B k gives effectively perfect discrimination. Optimal discrimination between quasi-orthogonal coherent states in experiments is customary and can be efficiently performed in the lab (see for example the M-ry phase encoding procedure or amplitude encoding scheme [28][29][30]).…”

New Quantum Cipher Optical Communication: Y-00

“…Y-00 encryption transmission equipment for 10 Gbps transmission based on optical intensity modulation has been developed in japan [30,31]. The design concept of this equipment is the same as the above-mentioned 2.4 Gbps transmission equipment except that dedicated high-speed devices have been developed to realize the equipment.…”

“…This evaluation has proved that the Y-00 transmission equipment is sufficiently applicable to 10 Gbps transmission. Thus we could obtain prospects for high-speed transmission [29,30,31].…”