Cryptography using dark-bright soliton to generate keys by orthogonal dark-bright soliton pair

Abstract

A method of optical cryptography by using soliton as dark-bright conversion control within a modified add/drop optical filter is proposed. In principle, the coincidence (orthogonal) dark-bright soliton pair has shown promising behaviors, especially when they propagate into the π/2 phase shifter, i.e. beamsplitter, π/2phase shift between bright and dark solitons is occurred and separated. Such behaviors can be used to form the orthogonal light modes (solitons), which can be useful for application of cryptography, where in this case the long distance cryptography can be easily managed. In this work we have derived and presented a concept of multi-orthogonal solitons generated by using dark-bright soliton pulses within the modified add/drop optical filter, which is known as a PANDA ring resonator. A pair of optical keys is randomly generated and transmitted into the transmission line, where finally the corrected keys between Alice (sender) and Bob(receiver) can be retrieved. By using the dark-bright soliton conversion control, the obtained output of the dynamic states can be used to randomly form the multi-orthogonal soliton pairs, which can be available for computer and communication security applications, especially for long distance link.