Signal all-optical encryption and decryption key distribution method based on optical fiber wavelength division multiplexing system

The invention discloses a signal all-optical encryption and decryption key distribution method based on an optical fiber wavelength division multiplexing system. The signal all-optical encryption and decryption key distribution method comprises the following steps of: 1) performing optical signal encryption transmission, and 2) performing optical signal decryption receiving. By the method, according to the characteristic of the optical fiber wavelength division multiplexing system and a stream cipher system theory, each path of optical signal is used as an encryption key for encrypting the next path of optical signal. The problem that a key generation unit is complicated because of a large number of keys of the encryption scheme and the problems of high security guaranteeing difficulty and high complexity of a key transmission process in the prior art can be solved.