Steganography using Mode-Based Least Significant Bit (MBLSB) Method

In the Least Significant Bit (LSB) method of steganography, inserting bits into the cover image is generally done using the blue channel while ignoring the red and green channels as the human eye is relatively insensitive to blue color as such making it easier to hide the secret bits. However this approach is also easier to be detected and therefore attacked as one can discover the secret bits by observing the size distribution in each channel of the cover image. Our work introduces a simple method that insert the secret bits into cover image based on mode value of the bits of all channels, as such the insertion is evenly distributed based on the cover image size and is harder to be detected or attacked. Our proposed MBLSB approach divides the cover image into several insertion blocks, of which each pixel value will be taken from all pixels in each channel. Finally a XOR gate is applied to the secret bit and the retrieved pixel value to get the mode value for the purpose of determining the insertion bit value. The resulting stego-image quality are evaluated using PSNR with value above 60 dB (no apparent noise) and MSE with value below 1.0 while the average success rate of secret data extraction in the event of a color noise attack is 66.45%.