In view of the limitations of the electric signal processing-based stream cipher encryption/decryption technology for optical communication security systems

this paper presents an all-optical signal processing-based encryption/decryption technology

studies several typical all-optical XOR encryption schemes and introduces their operating principles

characteristics and research advances.Then

it builds a simulation model for the SOA-MZI XOR gate-based all-optical encryption/decryption system using the OptiSystem software and optimizes the system by a optimization structure designed on the basis of the self-phase modulation effects of High Nonlinear Fiber（HNLF）.Studies show that the all-optical encryption/decryption technology has excellent performances and enables the entire security system to have higher operation rates and more secured transmissions.