High Performance Secured Image Transmission System Employing OFDM and Cryptography

In the modern world, it is vital to ensure that appropriate encryption and decryption are used while sending data across the internet to avoid unwanted access. Based on the visual cryptography system, a novel cryptographic scheme is suggested to secure color images. As inputs are a color image that needs to be protected and a binary image that serves as the encryption and decryption key. Three monochromatic images based on the $\mathrm{YC}_{\mathrm{b}} \mathrm{C}_{\mathrm{r}}$ color space are created from a secret color image that needs to be shared. Following the conversion of these monochromatic images into binary images, the binary images are then encrypted using binary key images, also known as share-l, to produce binary cipher images. Three half-tones of the secret color image and the binary key image are encrypted independently using the Exclusive OR technique. Share-2 is obtained by combining these binary pictures. After the shares have been encrypted, the binary images that have been retrieved are converted to inverted halftones and merged to create a hidden color image. This technique works better over a diffused channel for transmitting natural images. The OFDM technology is the foundation of this multi modal transmission. In wireless communications, OFDM as a multi-carrier transmission mechanism plays vital role. Due to its many benefits, including its fast data rate transmission, excellent reception quality, and capacity to counteract Inter-Symbol Interference (ISI), particularly in fading channels, the adoption of OFDM has grown significantly.A novel approach is put forward for progressive image transmission via Low Density Parity Check Coding (LDPC) on coded Orthogonal Frequency Division Multiplexing (OFDM) systems. In this technique, the Peak to Average Power Ratio (PAPR) of the OFDM signal is reduced and the performance of the OFDM systems is improved through the utilization of trigonometric transformations. It enhances progressive picture transmission’s ability for error resilience and transmission efficiency. This method uses the Lagrange interpolation technique to divide a single bit, “1,” into ($n-k+1)$ shares. To demonstrate the uniqueness of the suggested plan, a comparison with a few existing schemes is given.Using PAPR reduction techniques, the encrypted image is delivered safely when noise is reduced. Ultimately, the provided image from the internet is successfully recovered and captured..The computed mean square error and peak to signal noise ratio results are compared with the three color images. A rise in MSE is accompanied by an increase in PSNR.