Information Hiding in image and audio files

Abstract

The idea and practice of hiding information has a long history. Cryptography came into existence for securing the secrecy of communication and many methods were developed to encrypt and decrypt data in order to keep the data secret. Using Cryptography only scrambles the data so that it is converted into a form not understandable by normal observation or it is almost impossible to know the encrypted message without the key. Unfortunately it is sometimes not enough to keep the contents of a message secret, it may also be necessary to keep the existence of the message secret. The technique used to implement this, is called as Information Hiding or Steganography. A number of common methods of steganography are implemented and evaluated in spatial, transform domain and compressed domain using Image as well as Audio as the medium to hide Confidential Information. The strengths and weakness of the chosen methods are analyzed.