Steganoflage: A New Image Steganography Algorithm

Steganography is the science that involves communicating secret data in an appropriate multimedia carrier, e.g., image, audio and video files. It comes under the assumption that if the feature is visible, the point of attack is evident, thus the goal here is always to conceal the very existence of the embedded data. It does not replace cryptography but rather boosts the security using its obscurity features. Steganography has various useful applications. However, like any other science it can be used for ill intentions. It has been propelled to the forefront of current security techniques by the remarkable growth in computational power, the increase in security awareness, e.g., individuals, groups, agencies, government and through intellectual pursuit. Steganography?s ultimate objectives, which are undetectability, robustness, resistance to various image processing methods and compression, and capacity of the hidden data, are the main factors that separate it from related techniques such as watermarking and cryptography. This thesis investigates current state-of-the-art methods and provides a new and efficient approach to digital image steganography. It also establishes a robust steganographic system called Steganoflage. Steganoflage advocates an object-oriented approach in which skin-tone detected areas in the image are selected for embedding where possible. The key objectives of this thesis are: 1) a new image encryption method tailored to digital images and steganography/watermarking, 2) a new, efficient and realtime skin-tone detection algorithm and 3) a new embedding method using the Reflected Binary Gray Code, RBGC, in the wavelet domain. Each of these components is tested against relevant performance measurements. The results are promising and point to the advocacy and coherence of the developed algorithm. A series of interesting applications are shown, i.e., combating digital forgery, multilayer security for patients? data storage and transmission and digital reconstruction of lost signals. Future work includes the integration of Steganoflage into some emerging technologies, such as the iPhone and CCTV, which require further enhancements in relation to severe compression tolerance and real-time execution.