Security Through Blowfish and LSB Bit–Cycling With Mathematical Sequences

Recently, lots of research work and papers are focusing on the combination of steganography and cryptography. Steganography conceals the presence of a secret message. Cryptography scrambles the secret message so that no one can understand it except for the intended receiver. The combination of steganography and cryptography ensures a secure data transmission between the sender side and the receiver side. This paper proposes an RGB image steganography technique using a double-layer steganography and cryptography system that uses Blowfish for the cryptography layer and LSB for the steganography layer. The LSB substitution follows two mathematical sequences which are an arithmetic sequence and the Rudin-Shapiro sequence. The arithmetic sequence determines the pixel to be embedded and the Rudin-Shapiro sequence determines the color channel to be embedded. The steganography and cryptography system is also evaluated using some performance metrics which are the mean square error (MSE), the peak signal to noise ratio (PSNR), the correlation, the image quality index (Q), the entropy, the image histogram, the structural similarity index measurement (SSIM), the R measurement, the normalized cross correlation (NCC) and the image fidelity (IF). In addition, a comparison between the proposed scheme and other proposed work from the literature is presented to show that the proposed scheme has a very good performance that is better than its counterparts from the literature.