This thesis implements a steganographic method which encrypts the secret message by exponential and modular operations before hiding data to improve the security. For the cover image, we also do an affine transform based on the locations of pixels before embedding the bits. The secret message encryption is a sequence of bits obtained from shuffling the bits of the secret message according to the concept of an exponential and modular arithmetic. We first select a prime number p and convert a secret message into many sets of a bit sequence S[i], 1 S[i]