Optical transmission device and reception device for Yuen encryption, optical transmission method and reception method for Yuen encryption, and encrypted communication system

摘要

A configuration method of an optical signal, an encryption device, and an encryption system makes it possible for a legitimate communicating party to ensure information-theoretic security against a known plain text attack and to communicate long-distance. By adding a transmission information data sequence randomization device to the Yuen encrypted communications device according to the present information, which divides transmission information data into blocks, appends sequence numbers thereto, randomly switches the sequence of the blocks with a digitized signal of output of an electrical noise generator, and inputs same into a transmission data generator of a conventional Yuen encrypted optical transmitter, the relation between a known transmission information data sequence (plain text) and an optical signal which is outputted from the transmitter is randomized, allowing forcibly making even a circumstance wherein a known-plain text attack would be possible into a cipher-text-only attack, realizing information-theoretic security against a known-plain text attack.

主权项

1. A Yuen encryption optical transmission device, which is connected with an optical communication pathway, for implementing Yuen-2000 encryption (Y-00) protocol, the optical transmission device comprising:
a transmission information data sequence randomization device for generating transmission information using Y-00 protocol, the transmission information data sequence randomization device comprising: a data sequence block divider for dividing input information into one or more blocks, a sequence number appender for appending a sequence number to the blocks and packetizing the same, and a sequence converter for randomizing and sorting the sequence of the packets using an output sequence of an electrical noise generator; a transmission data generator connected with the transmission information data sequence randomization device, the transmission data generator configured to generate transmission data configured by 0s and 1s of information bit based on the transmission information; a pseudorandom bit generator configured to generate a pseudorandom bit sequence from an initial key; a base selection controller connected with the pseudorandom bit generator, the base selection controller configured to hold a base group configured by a number of bases and to select one base from the base group in conformity with the pseudorandom bits sequence; and an intensity optical modulator connected with the transmission data generator and the base selection controller, the intensity optical modulator configured to generate an optical modulation signal based on the transmission information using two optical intensities corresponding to the one selected base, and to output the optical modulation signal to the optical communication pathway, wherein in all of the bases constituting the base group, the two optical signal intensities corresponding to each of the bases have values above and below an interposed intermediate point of a maximum intensity and a minimum intensity, the intensities of signal group above the intermediate point being deployed concentrated in the vicinity of the maximum intensity and the intensities of signal group below the intermediate point being deployed concentrated in the vicinity of the minimum intensity, and the range of the intensities of the signal group above the intermediate point and the range of the intensities of the signal group below the intermediate point are set so as to be entirely hidden by quantum shot noise appearing in proportion to energy in the vicinity of the intensities of each signal group.