The drawback with cloud computing is the security challenges since the data in the cloud are managed by third party. Steganography and cryptography are Steganography and cryptography are some of the security measures applied in the cloud to secure user data.
Pulse code modulation or other Digital Carrier Methods There are many ways in which messages can be hidden in digital media.
Digital forensics examiners are familiar with data that remains in file slack or unallocated space as the remnants of previous files, and programs can be written to access slack and unallocated space directly. Small amounts of data can also be hidden in the unused portion of file headers Curran and Bailey Information can also be hidden on a hard drive in a secret partition.
A hidden partition will not be seen under normal circumstances, although disk configuration and other tools might allow complete access to the hidden partition Johnson et al.
This theory has been implemented in a steganographic ext2fs file system for Linux. A hidden file system is particularly interesting because it protects the user from being inextricably tied to certain information on their hard drive.
This form of plausible deniability allows a user to claim to not be in possession of certain information or to claim that certain events never occurred. Under this system users can hide the number of files on the drive, guarantee the secrecy of the files' contents, and not disrupt nonhidden files by the removal of the steganography file driver Anderson et al.
Another digital carrier can be the network protocols. Covert Transmission Control Protocol by Craig Rowland, for example, forms covert communications channels using the Identification field in Internet Protocol packets or Steganography research papers sequence number field in Transmission Control Protocol segments Johnson et al.
There are several characteristics of sound that can be altered in ways that are indiscernible to human senses, and these slight alterations, such as tiny shifts in phase angle, speech cadence, and frequency, can transport hidden information Curran and Bailey Nevertheless, image and audio files remain the easiest and most common carrier media on the Internet because of the plethora of potential carrier files already in existence, the ability to create an infinite number of new carrier files, and the easy access to steganography software that will operate on these carriers.
For that reason, the manuscript focus will return to image and audio files.
The most common steganography method in audio and image files employs some type of least significant bit substitution or overwriting. The least significant bit term comes from the numeric significance of the bits in a byte.
The high-order or most significant bit is the one with the highest arithmetic value i. As a simple example of least significant bit substitution, imagine "hiding" the character 'G' across the following eight bytes of a carrier file the least significant bits are underlined: These eight bits can be "written" to the least significant bit of each of the eight carrier bytes as follows: This makes some sense when one set of zeros and ones are being substituted with another set of zeros and ones.
By overwriting the least significant bit, the numeric value of the byte changes very little and is least likely to be detected by the human eye or ear. Least significant bit substitution is a simple, albeit common, technique for steganography.
Its use, however, is not necessarily as simplistic as the method sounds. Only the most naive steganography software would merely overwrite every least significant bit with hidden data. Almost all use some sort of means to randomize the actual bits in the carrier file that are modified.
This is one of the factors that makes steganography detection so difficult.
One other way to hide information in a paletted image is to alter the order of the colors in the palette or use least significant bit encoding on the palette colors rather than on the image data. These methods are potentially weak, however.
Many graphics software tools order the palette colors by frequency, luminance, or other parameter, and a randomly ordered palette stands out under statistical analysis Fridrich and Du Newer, more complex steganography methods continue to emerge.
Spread-spectrum steganography methods are analogous to spread-spectrum radio transmissions developed in World War II and commonly used in data communications systems today where the "energy" of the signal is spread across a wide-frequency spectrum rather than focused on a single frequency, in an effort to make detection and jamming of the signal harder.
Spread-spectrum steganography has the same function-avoid detection. These methods take advantage of the fact that little distortions to image and sound files are least detectable in the high-energy portions of the carrier i.
Steganography Examples There are more than steganography programs currently available, ranging from free downloads to commercial products. This map is hidden in the various carriers in this article. A GIF carrier file containing the airport map. The first example employs Gif-It-Up, a Nelsonsoft program that hides information in GIF files using least significant bit substitution and includes an encryption option.
The original carrier isbytes in length and uses unique colors, whereas the steganography file isbytes in length and uses unique colors.
The file size is larger in the steganography file because of a color extension option used to minimize distortion in the steganography image.
If color extension is not employed, the file size differences are slightly less noticeable. The palette from the Washington mall carrier file before left and after right the map file was hidden. Figure 7 shows the carrier file's palettes before and after message insertion.benjaminpohle.com Mathematics "All things in nature occur mathematically" Our Master of Science in Mathematics (MSMTH) program provides students with rigorous and thorough knowledge of a broad range of pure and applied areas of mathematics.
A Review on Image Steganography. 1Savita, 2 Mamta Juneja 1ME, This paper includes the important steganography methods and the main focus is on the review of ste-ganography in digital images.
Terms used in the paper are M message, C cover image, Z stego image, E International Journal of Scientific & Engineering Research Volume 4, Issue. ieee paper engineering research papers free download IEEE PAPER steganography IEEE PAPER AND ENGINEERING RESEARCH PAPERS ==Phrack Inc.== Volume 0x0f, Issue 0x45, Phile #0x0a of 0x10 |==| |==[ The Art of Exploitation ]==| |==| |=--=[ Self-patching Microsoft XML with.
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