A new horizon in data security by Cryptography & Steganography

Steganography and Cryptography are two popular ways of sending vital information in a secret way. One hides the existence of the message and the other distorts the message itself. There are many cryptographic techniques available and among them AES is one of the most powerful techniques. In Steganography, various techniques in different domains like spatial domain, frequency domain etc are available to hide messages. It is very difficult to detect hidden message in frequency domain and for this domain various transformations like DCT, FFT, Wavelets etc are available. In this paper we propose a new technique in which Cryptography and Steganography are used as integrated part along with newly enhanced security module for transmitting text. Before encryption we are using Huffman compression technique to compress the input plain text and compressed text is encrypted using advanced encryption standard (AES. After encryption, a part of the compressed encrypted message (cipher) is hidden in DCT of an image; remaining part of the cipher is used as a secret key to regenerate the cipher text. Introduction of compression technique improves the data hiding capacity and partial cipher hiding in stego-image make this system more secured. Keyword: Cryptography, Steganography, Stegoimage, Compression, Threshold Value, DCT Coefficient