The abundant digital data access through Internet has raised the issue of secured data transmission. The most promising methods for secured data transmission are Steganography and cryptography. In cryptography technique makes the data unintelligible and in steganography technique the secret message is hidden. The excellent carriers of hidden information is through Digital Images. In this proposed approach the steganography and cryptography technique are combined together as high-performance JPEG steganography along with a substitution encryption methodology. A discrete cosine transform (DCT) technique is used with frequency domain for hiding encrypted data within image. Based on the experimental analysis the encrypted visual and the statistical values of the image before the insertion is similar to the values after insertion and reduces the chance of the confidential message being detected and enables the secret communication. The proposed methodology analyzes the Mean square error (MSE) and Peak Signal to Noise Ratio (PSNR) to estimate the effectiveness of proposed method.