Encryption based LSB Steganography Technique for Digital Images and Text Data

Digital steganography is the art and science of hiding communications; a steganographic system thus embeds secret data in public cover media so as not to arouse an eavesdropper’s suspicion. A steganographic system has two main aspects: steganographic capacity and imperceptibility. However, these two characteristics are at odds with each other. Furthermore, it is quite difficult to increase the steganographic capacity and simultaneously maintain the imperceptibility of a steganographic system. Additionally, there are still very limited methods of Steganography to be used with communication protocols, which represent unconventional but promising Steganography mediums. Digital image Steganography, as a method of secret communication, aims to convey a large amount of secret data, relatively to the size of cover image, between communicating parties. Additionally, it aims to avoid the suspicion of noncommunicating parties to this kind of communication. Thus, this research addresses and proposes some methods to improve these fundamental aspects of digital image Steganography. Hence, some characteristics and properties of digital images have been employed to increase the steganographic capacity and enhance the stego image quality (imperceptibility). Here, the research aim is identified based on the established definition of the research problem and motivations. Unlike encryption, Steganography hides the very existence of secret information rather than hiding its meaning only. Image based Steganography is the most common system used since digital images are widely used over the Internet and Web. However, the capacity is mostly limited and restricted by the size of cover images. In addition, there is a tradeoff between both steganographic capacity and stego image quality. Therefore, increasing steganographic capacity and enhancing stego image quality are still challenges, and this is exactly our research main aim. To get a high steganographic capacity, novel Steganography methods were proposed. The first method was based on using 8x8 non-overlapping blocks and quantization table for DCT with compression. Second method incorporates the DWT technique, with quality of any stego images as enhanced to get correct hidden image. And last LSB as to store images with Key type security built in. Keyword digital images, hidden, Steganography, encryption, steganographic