Image Encryption and Compression using Embedding Technique

Encryption is used to securely transmit data in open networks. Each type of data has its own features; therefore different techniques should be used to protect confidential image data from unauthorized access. Most of the available encryption algorithms are mainly used for textual data and may not be suitable for multimedia data such as images. For secure transmission, various compression and encryption techniques are proposed to satisfy a fast and secure transmission. However these two techniques must be studied separately. In this paper we propose a method combining encryption and compression based on Embedding and Extracting and Discrete Cosine Transform (DCT). For encryption, target images are covered with an insignificant image to hide them and it is transmitted to destination. The receiver reconstructs the original images by extracting the insignificant image. For compression process, using DCT the size of transmission can be reduced. Through several computer simulations, the performance of the proposed method is confirmed.