Improved Security Based on Combined Encryption and Steganography Techniques

Abstract

For some people a science, for other people just an art, steganography is in fact an ancient method of embedding a message into an apparently uninteresting carrier. Aiming to protect information, steganography is considered to be a close relative of encryption although they have different approaches. While encryption scrambles the message based on a certain algorithm so it can't be understood by anyone that does not hold the unscrambling key, steganography works on hiding the message without the need to deteriorate it. Minor alteration of the carrier file is accepted since steganography does not affect its useful content. Actually, steganography exploits file redundancy, file headers or, in case of multimedia content, replaces information that can't be used or perceived by the human eyes or ears. In this paper, a combination of image based steganography with encryption is presented. The encryption and decryption are based on two different files in which, by steganographic means, important information is hidden. The original message (the secret message) can be restored only if both files arrive safe at destination. There are no constraints regarding the image file types. The most important contribution resides in how the original information is encrypted and embedded into different graphic files, sent to the destination through different channels and then restored. Comparative performance tests were performed.