부산대학교 도서관

Protection of information in modern telecommunication systems and systems of information storage plays significant part. Maximal effectiveness of information protection can be achieved by steganographic transforms, which hide the fact of information transaction. The methods of information embedding are determined by container signal (image, video, audio, text e. t. c.). Steganographic container (loaded container) has to be stable for the special attacks. To provide effective decoding of received stego-container, receiving side has to know decoding algorithm and sufficient number of transform keys. Effective way to complicate decoding of stego-container by intruder is using of chaotic container. But in this case the task of decoding by receiving side may become difficult. If receiving side uses generator of chaotic signal, it must be synchronized with generator on sending side. In case when receiving side doesn't know chaotic container signal, the task of decoding is equal to steganographic analysis and require significant data processing. Perspective way of steganographic systems with chaotic container implementation is using of invariant transform. Information redundancy allows invariant decoding with absolute accuracy, limited by number of digits of telecommunication channel. Information redundancy achieved by multi-component stego-container or two-component stego-container in particular case. Invariant transform based on contraction mapping method allows implementation of non-linear steganographic systems with information redundancy. In this systems decoding algorithm can be pretty simple, but they can provide a number of key coefficients with very high sensibility of system to their modification, so it is necessary to know coefficients for effective detection of embedded information.