Steganographic file systems
Steganographic file systems were first proposed by Ross Anderson, Roger Needham, and Adi Shamir. Their paper proposed two methods of hiding data: in a series of fixed size files originally consisting of random bits on top of which 'vectors' could be superimposed in such a way as to allow levels of security to decrypt all lower levels but not even know of the existence of any higher levels, or an entire partition is filled with random bits and files hidden in it.
A steganographic file system must meet three basic requirements. First, like any file system, it must be able to manage the storage of files on a disk. Second, it must provide a mechanism for hiding files. This allows a user to plausibly deny the number of files stored on disk. Third, it must provide a mechanism for accessing files that have been hidden.
Steganograpy of VoIP Streams
Voice over Internet Protocol (VoIP) streams, are broadcasted live over the Internet and delivered to end-users. Security remains one of the main challenges with this new technology. With the upsurge of VoIP applications available for use in recent years, VoIP streams become one of the most interesting cover objects for modern steganography. Digital steganography in low bit rate audio streams is commonly regarded as a challenging topic in the field of data hiding.
BPCS Steganography (Bit-Plane Complexity Segmentation Steganography)
BPCS Steganography is a type of digital steganography. Digital steganography can hide confidential data very securely by embedding them into some media data (vessel data). In BPCS Steganography true color images (i.e., 24-bit color images) are mostly used for vessel data. The embedding operation in practice is to replace the "complex areas" on the bit planes of the vessel image with the confidential data. The most important aspect of this type of steganography is that the embedding capacity is very large.
Steganalysis is the art and science of detecting messages hidden using steganography; this is analogous to cryptanalysis applied to cryptography.
Hiding Model and Algorithm
Steganography takes advantage of the redundancy of data in the cover media to insert the “extra” information so that there could be no perceptible change to the cover media.
Extraction Model and Algorithm
The extraction process should be possible without the cover. The extraction algorithm can also be applied on any cover, whether or not it contains a secret message. In the latter case, the output of the extraction process is considered as a “natural randomness” of the cover.