Cryptography in Optical network using Secrecy Scheme

Abstract

In modern times, the exchange of data takes place through various methods. One such method for
secure exchange of confidential data is the encryption. Optical encryption is less complex and
offers higher data rates than electronic encryption. But efficient exchange of confidential
information with perfect secrecy is still a concern. We have demonstrated two encryption modes,
including a scheme providing perfect secrecy. We employed the concept of optical logic gates for
encryption and decryption processes. To overcome eavesdropping of the data, the optical
information network with EXOR encryption scheme is modified by including a “secrecy layer”
that modulate the phase of the data in addition to generating the key, so that the eavesdropper
cannot derive any information about the actual data. Thus encryption and decryption of optical
information can be done in a secure manner. Also the effect of dispersion on optical fibers is
analyses and optimum dispersion value is found to reduce nonlinearities and to decrypt the data
correctly at the receiver side. The simulation of the proposed method is carried out in Optisystem
software. The simulated results of the encryption and decryption of data using optical EXOR gate
and by using secrecy layer are obtained and tabulated. It is shown that the concept of secrecy
layer for encryption and decryption is more secure than the other method using EXOR gate. The
maximum Q-factor obtained for the secrecy scheme is 8.48493 dB and the Bit Error rate value
obtained is 7.43771e-018.