Encryption Using Optical Pseudo-Random Binary Sequence Based on Optical Logic Gate

Abstract

In this paper, we propose a scheme for high-speed all-optical Pseudo-Random Binary Sequence (PRBS) generator and use it for generating keystream for encryption. This PRBS generator design is based on Linear Feedback Shift Registers (LFSR) and optical XOR and AND gates. The optical logical gates are based on quantum dot-semiconductor optical amplifier Mach-Zehnder interferometer (QD-SOA-MZI). With two photon absorption (TPA) in quantum dot-semiconductor optical amplifier (QD-SOA), this kind of optical logic gates performs well when processing data in an ultra-fast timescale and therefore able to function as high speed PRBS generator. Result shows that it’s possible for this scheme to realize all-optical encryption and decryption at high process rate up to 320 Gb/s. We simulated different ways of generating keystream with schemes such as cascaded generator, parallel generator and alternating step generator. These generators use more than one LFSR. Result shows that the schemes we use can function as stable and complex keystream generators.