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Computers Talk Binary. nd/Binary_Conversion/Binary_to_Text.asp Send me a polite or write me a polite coded.

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Presentation on theme: "Computers Talk Binary. nd/Binary_Conversion/Binary_to_Text.asp Send me a polite or write me a polite coded."— Presentation transcript:

1 Computers Talk Binary

2 nd/Binary_Conversion/Binary_to_Text.asp Send me a polite or write me a polite coded binary message ractive.com/PlayGrou nd/Binary_Conversion /Binary_to_Text.asp

3 Even Pictures are Binary

4 Steganography

5

6 Steganography Means covered writing dates back to ancient Greece –common practices –etching messages in wooden tablets and covering them with wax –tattooing a shaved messenger's head, letting his hair grow back, then shaving it again when he arrived at his contact point

7 Other codes Breaking the code carved into the ceiling of the Rosslyn Chapel in Scotland reveals a series of musical passages.

8 “invisible writing” Another common form of Steganography is through the use of Invisible inks. Such inks were used with much success as recently as WWII. An innocent letter may contain a very different message written between the lines Can you see me Early in WWII steganographic technology consisted almost exclusively of invisible inks [Kahn67]. Common sources for invisible inks are milk, vinegar, fruit juices and urine. All of these darken when heated.

9 Steganography Art and science of disguising or hiding information in the form of something else –embedding messages within other text –images or information may be encoded into pictures or texts files The “invisible” files can be (compiled and) retrieved by those with code

10 Embedding Messages Within Other Text Fishing freshwater bends and saltwater coasts rewards anyone feeling stressed. Resourceful anglers usually find masterful leapers fun and admit swordfish rank overwhelming anyday. By taking the third letter in each word, the following message emerges Send Lawyers, Guns, and Money. Null ciphers (unencrypted messages). The real message is "camouflaged" in an innocent sounding message. Source:

11 The following message was actually sent by a German Spy in WWII Apparently neutral's protest is thoroughly discounted and ignored. Isman hard hit. Blockade issue affects pretext for embargo on by products, ejecting suets and vegetable oils. Taking the second letter in each word the following message emerges: Pershing sails from NY June 1 Source:

12 Word-Shifting Expand the space before explore, the, wide, and web by one point and condensing the space after explore, world, wide and web by one point in sentence S1. By overlapping the two messages you get: We explore new steganographic and cryptographic algorithms and techniques throughout the world to produce wide variety and security in the electronic web called the Internet.

13 Embedding Text in Pictures

14 Embedding Messages within photos The larger the given message is relative to the hidden message, the easier it is to hide it For this reason, digital pictures (which contain large amounts of data) are used to hide messages on the Internet and on other communication media.digital picturesInternet a 24-bit bitmap will have 8 bits representing each of the three color values (red, green, and blue) at each pixel.bitmappixel If we consider just the blue there will be 28 different values of blue. The difference between and in the value for blue intensity is likely to be undetectable by the human eye. Therefore, the least significant bit can be used (more or less undetectably) for something else other than color information. If we do it with the green and the red as well we can get one letter of ASCII text for every three pixels.least significant bit ASCIIpixels

15 Can you tell the difference?

16 With your parents help SOURCE: AND


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