Information hiding in images using Discrete Cosine Transform

Abstract

In this era of development and increasing use of the Internet, user facing security problem during information sharing in which unauthorized receivers can gain access to the information transmitted. Data hiding during the transmission of information via the internet is one of the techniques used to keep the secrecy of the information to the unauthorized/ unintended persons. Steganography is a way of hiding secrets information by inserting it into an audio, video, image or text file without raising any suspicious to unintended persons. This paper presents the study which hides text messages into the image file by using Discrete Cosine Transform (DCT) steganography method. The method of this work by transforming the cover image and text message from spatial domain to frequency domain and use redundant bit of cover image to hide text message in such a way that unintended person will continue to see it as a normal image. The method continues to keep the quality of the cover image which transfers the information to reduce suspicion. Steganography is most used in military, law enforcement agency, corporate spies and in the medical area for hiding sensitive information.