Data Security Using Cryptosteganography in Web Application

Abstract

Data security using Cryptosteganography in web application is a web based application used to conceal important information through hybrid cryptography and Steganography and provide means of its secure transmission through any medium or channel .Using a web browser the user uploads the important information and an envelope image. The same is received by the Data Shielder facade web application .The web application sends the data and envelope image to the real Data Shielder .It generates a unique key and encrypts the crucial data .The key is associated with a "unique id" and preserved in a store .Then the encrypted information is embedded into the envelope image using modified BPCS technique .Finally a stego image is generated .Data Shielder returns the "unique id" and stego image to the facade web application .Web application further archives the stego image and unique key and allows the user to download it. The user can simply unzip the archive and transmit the stego image through unsecured channels like email, sockets, pen drives, cds, dvds, etc. And can keep the unique id safe. When the user wants its data back then user needs to upload the stego image and the "unique id" to the Data Shielder facade web application. The web application sends the unique id and stego image to the real Data Shielder. First it finds the encryption key from the store through the unique id. Next, reversing the BPCS Steganography, the stego image is processed and encrypted data is fetched. Finally using the encryption key decryption is done and the crucial data is fetched back. The same is returned to the facade web application, which is rendered to the user.

Keywords: Cryptography, Steganography, Stego- image, Threshold Value