Information hiding-a survey

Abstract

Information hiding techniques have recently become important in a number of application areas. Digital audio, video, and pictures are increasingly furnished with distinguishing but imperceptible marks, which may contain a hidden copyright notice or serial number or even help to prevent unauthorised copying directly. Military communications systems make increasing use of traffic security techniques which, rather than merely concealing the content of a message using encryption, seek to conceal its sender, its receiver or its very existence. Similar techniques are used in some mobile phone systems and schemes proposed for digital elections. Criminals try to use whatever traffic security properties are provided intentionally or otherwise in the available communications systems, and police forces try to restrict their use. However, many of the techniques proposed in this young and rapidly evolving field can trace their history back to antiquity; and many of them are surprisingly easy to circumvent. In this article, we try to give an overview of the field; of what we know, what works, what does not, and what are the interesting topics for research.

Steganography and Encryption Systems Based on Spatial Correlators with Meaningful Output Images

“…This feature is different from other known codes, such as the common bar code. Another application might be embedding steganographic information [17][18][19] in halftone pictures. The ordinary visible image is conventionally encoded by the dots' sizes, whereas the steganographic image is encoded by their positions.…”

“…The window's area is smaller than, or equal to, the area of the output plane. Similarly, in the input plane, projection P 2 onto the constraint set at the jth iteration is 19) where exp[iθ j (x, y)] is the phase function of g j (x, y) at the jth iteration. The iteration process is shown schematically in Figure 4.…”

Hiding a Needle in a Haystack Using Negative Databases

“…Information Hiding techniques [3,19] like water-marking and steganography [15] focus on concealing data items within some stream of information (while, in a matter of speaking, ours hides information in the garbage). Our approach is similar to these techniques in that, given a negative database, it is infeasible to determine whether it represents any valid string (message) at all, i.e., if the corresponding positive database is non-empty; and in that knowledge of the existence of a message does not facilitate its retrieval.…”

Adaptive Randomization in Image Steganography Pertaining to Most Significant Nibble

“…The strength of steganography can be improved by combining it with cryptography. The two close associates of steganography are watermarking [14,16] and fingerprinting which are widely used in copyright protection [15]. The main deviation of copyright protection from steganography is the presence of message is often known but robust to remove where as in a steganographic scheme imperceptibility is the crucial factor.…”

“…However the existence of communication is known to the snooper and this may lead to attempts to decrypt, modify or destroy the data. This lead to evaluation of new technique called STEGANOGRAPHY [1-5, 7, 9, 16, 20] which expends data hiding [14,16,17].The word steganography was adopted from Greek literature which means -covered writing‖ [2,3]. The usage of steganographic techniques dates back to prehistoric periods which refer to usage of invisible inks, text on wax-covered tablets, communicating hidden messages in music etc.…”