Information hiding scheme for digital images using difference expansion and modulus function

Disguising the presence of communication has become a severe concern in this highly digitalized world due to the unauthorized data access and network policy violations that are emerging rapidly. These issues have led to the application of cryptography technique as a mean for securing data by encrypting them. However, since the encrypted data can be seen by sophisticated intruders during the transmission, this may lead to its suspicion which can results in unauthorized access. Thereby, steganography is another technique for securing communication. Steganography is the practice of concealing confidential information in the codes that make up digital files. Different from encryption, however, steganography provides security by disguising the presence of communication. In this context, this paper presents an improved information hiding implemented based on difference expansion and modulus function. The previous method has only considered the image smooth areas where the difference value is 0 or 1 while ignoring other values for hiding data. These limitations may result in decreasing the embedding capacity for all images having few smooth areas. Hence, a new scheme that considers both positive and negative difference values to conceal secret data is developed. The experimental results prove that the proposed scheme achieves better results than the existing methods.