Hiding secret in parity check bits by applying XOR Function

In this paper, we propose a hybrid data hiding method to embed three secret bits to four cover pixels. In the proposed method, a Hamming code word consists of three parity check bits whose values are identical to three secret bits and four data bits whose values are derived by performing XOR Function on four cover pixels. In order to keep the Hamming code word satisfying the condition of (7, 4) Hamming Code, at most one cover pixel would be modified. If the modified bit is a data bit of the code word, it is directly modified, and three secret bits can be embedded to the cover pixels successfully. However, if the modified bit is a parity check bit, namely the secret bit, instead of modifying the parity check bit, two cover pixels are needed to be modified while the proposed method only requires one bit modification by adopting the XOR Function. Our hybrid method only need to modify one cover pixel by adding/subtracting its values to/from one, and two resultant bits of XOR Function are able to be adjusted to the desired bits. In this way, the number of modified pixels can be further reduced. The experimental results show that the number of pixels that undergo modification during the embedding phase is fewer by using the proposed method than using the other two related method in most cases.