To ensure reliability and integrity in information transmission, image steganography is cutting edge technology in today's digital world. It can be implemented in spatial, time and frequency domain. In this research article, an effective algorithm has been introduced which would embed secret message data, scrambled by Arnold Transform, in frequency domain using the quantization coefficient modification in Discrete Cosine Transform (DCT). At first the cover image is split into blocks, then two dimensional DCT is applied on each image block and transformed secret message is inserted by analyzing mid-band coefficients of DCT. After the successful transmission of the cover image to the recipient, the secret message can be effectively recovered in high quality from the Stego image. © 2015 IEEE.