Application of modify RSA cryptography and randomly LSB steganography on color images of fluid flow in a channel

This paper introduces a combination of three methods including a modified RSA cryptography, hidden text using steganography, and selection of random pixel from image to improve the general security level of the system. In this regard, the image is a carrier of the information transmitted through the media, and the fluid motion image is used to hide the information after it was encoded using modify RSA technique that before hiding it in a random way, because the image of fluid motion possesses the sinusoidal waves and turbulent motion.  In this paper, a combination of three techniques is utilized in order to prevent the intruders and attackers from detecting the information and sharing it with others. LSB technique is used for hiding the message in image-based steganography. In addition, pseudo number to choose the random number of pixel when hiding the message after encryption. Four measures including Peak Signal to Noise Ratio (PSNR), Mean Squared Error (MSE), Structural Similarity Index Measure (SSIM), and histogram are used to compare the original image and stego-image. The results demonstrated the outperformance of the proposed method so that neither the attacker nor the intruder could discover the information contained within the image, due to the large value of the PSNR, very small value of the MSE, stability of the SSIM, and matching the histograms.