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The same image viewed by white, blue, green, and red lights reveals different hidden numbers. Steganography (/ ˌ s t ɛ ɡ ə ˈ n ɒ ɡ r ə f i / ⓘ STEG-ə-NOG-rə-fee) is the practice of representing information within another message or physical object, in such a manner that the presence of the concealed information would not be evident to an unsuspecting person's examination.
The problem is generally handled with statistical analysis. A set of unmodified files of the same type, and ideally from the same source (for example, the same model of digital camera, or if possible, the same digital camera; digital audio from a CD MP3 files have been "ripped" from; etc.) as the set being inspected, are analyzed for various statistics.
A Type 1 Product refers to an NSA endorsed classified or controlled cryptographic item for classified or sensitive U.S. government information, including cryptographic equipment, assembly or component classified or certified by NSA for encrypting and decrypting classified and sensitive national security information when appropriately keyed.
The word cryptography became the more familiar term for secret communications from the middle of the 17th century. Earlier, the word steganography was common. [citation needed] The other general term for secret writing was cypher - also spelt cipher. There is a modern distinction between cryptography and steganography
Cryptography is also a branch of engineering, but an unusual one since it deals with active, intelligent, and malevolent opposition; other kinds of engineering (e.g., civil or chemical engineering) need deal only with neutral natural forces. There is also active research examining the relationship between cryptographic problems and quantum physics.
In classical cryptography, a null is an extra character intended to confuse the cryptanalyst.In the most common form of a null cipher, the plaintext is included within the ciphertext and one needs to discard certain characters in order to decrypt the message (such as first letter, last letter, third letter of every second word, etc.) [1] Most characters in such a cryptogram are nulls, only ...
Steganography tools aim to ensure robustness against modern forensic methods, such as statistical steganalysis. Such robustness may be achieved by a balanced mix of: a stream-based cryptography process; a data whitening process; an encoding process.
The information to be embedded in a signal is called a digital watermark, although in some contexts the phrase digital watermark means the difference between the watermarked signal and the cover signal. The signal where the watermark is to be embedded is called the host signal. A watermarking system is usually divided into three distinct steps ...