Single-mismatch 2LSB embedding steganography

This paper proposes a new method of 2LSB embedding steganography in still images. The proposed method considers a single mismatch in each 2LSB embedding between the 2LSB of the pixel value and 2-bits of the secret message, while the 2LSB replacement overwrites the 2LSB of the image's pixel value with 2-bits of the secret message. The number of bit-changes needed for the proposed method is 0.375 bits from the pixel values of the cover image, which is less than the 0.5 bits of 2LSB replacement. It also reduces the effect of 2LSB embedding pattern of change, which results in lower probability of detection by 44% according to the experimental results.