Data Security through more robust DCT based methodology and Assessment in terms of PSNR

This paper presents a new frequency domain approach for steganography algorithm. The proposed system proved to be more robust than the existing systems and calculates its PSNR, MSE, CER and Correlation coefficient. This paper also analyse the Least Significant Bit (LSB) spatial domain based Steganography and Discrete Cosine Transform (DCT) frequency domain based Steganography. LSB based Steganography embed the text message in least significant bits of digital picture. Least significant bit (LSB) insertion is a common, simple approach to embedding information in a cover file. Unfortunately, it is vulnerable to even a small image manipulation. DCT based Steganography embed the text message in least significant bits of the Discrete Cosine (DC) coefficient of digital picture. In DCT technique, message is hidden in more significant areas of cover image. An implementation of both these methods and DCT based proposed method with their performance analysis ( in terms of PSNR) has been done in this paper. Also different types of attacks such as salt and pepper noise has been applied. In these techniques, a trade-off between the amount of data to be hidden and the robustness of the image will be observed