Design of Secured Image Transmission Scheme Based on Cryptography in Different Communication Channels

Abstract

The need for establishing a network with privacy and security is gaining much at traction in this modern age. Illegal Data access or confidentiality breach is a serious threat that is prevalent in both wireless and wired communication channels. Due to the optic fiber’s attributes, such as its high bandwidth, reliability, and immunity to in terference, optical fiber networks can offer secure data transmission and are utilised in a variety of sensitive applications over long and small distances. However, there exists several types of fiber optic eavesdropping attacks. Eavesdropping is major physical layer attack occurs on all network, primarily targeting to obtain highly confidential information shared by government authorities, military, financial or pharmaceutical sectors. In this work an efficient solution to eavesdropping attacks during image trans mission is proposed. User data or the original image is encrypted using algorithmic cryptography (AES algorithm) and then transmitted over communication channel. In fiber optic channel, Optical CDMA is used to encode the signal Which acts as an additional Encryption layer in the network. Only the authorized user is permitted to retrieve the actual image correctly using matched decoder and correct decryption key in an AES- OCDMA system. The interception time for the eavesdropper will be high as they have to check each optical code and every possible encryption key which will eventually lead to low success rate of interceptor. Further, the encrypted image can also be transmitted over a OFDM to set up a high speed secure network.The en cryption quality of images in AES- OFDM scheme transmitted over AWGN channel is obtained with MATLAB and is defined in terms of Histograms and PSNR value. Optical OFDM system secured with crytographic algorithms is worth studying in the future