ADVANCED CRYPTOGRAPHY-STEGANOGRAPHY

摘要

Steganography literally means "covered Writing". It is defined as "hiding the information of messagernbeyond the picture or embedding the message with picture". It is the latest and advanced technology inrncryptography. It provides security for transforming the message over a network. The network may bernLAN, WAN, Internet etc., The steganography exists from olden days, the militants used waxed tablets forrnexchanging the codes during wars. Today, the encryption is mostly used for security. This paper deals withrnsteganography in two different forms namely Image with Text (IWT) and Text With Text (TWT). In IWT,rnthe message or information is hidden with in the image by some combination of bit values in such a wayrnthat the appearance of the original image will not be affected. The encoded image file is 99.99% looks likernoriginal image file. It is "virtually uncrackable". IN TWT, two texts are used, one is duplicate text that isrngoing to be encrypted and another one is the original message. The original text is inside the encryptedrnduplicate text. If someone see the encrypted duplicate text, he may assume this as the encrypted originalrntext by mistake. If he tries to decrypt it and if he succeeds, he will get only the duplicate text. Then hernassumes that the duplicate text is the original text. So, he won't try to trace the original text. This methodrnis complex than the existing methods. The above two concepts will increase the security.