Computers Talk Binary

http://www.roubaixinteractive.com/PlayGround/Binary_Conversion/

Binary_to_Text.asp• Send me a polite or

write me a polite coded binary message

• dpruitt@umd.edu• http://

www.roubaixinteractive.com/PlayGround/Binary_Conversion/Binary_to_Text.asp

Even Pictures are Binary

Steganography

http://www.wired.com/wired/archive/7.07/what.html

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

Other codes

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

http://science.howstuffworks.com/code-breaker.htm/printable

“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.

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

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: http://www.jjtc.com/stegdoc/sec202.html

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: http://www.jjtc.com/stegdoc/sec202.html

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.

Embedding Text in Pictures

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.

• a 24-bit bitmap will have 8 bits representing each of the three color values (red, green, and blue) at each pixel.

• If we consider just the blue there will be 28 different values of blue. • The difference between 11111111 and 11111110 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.

Can you tell the difference?

With your parents help

SOURCE: http://mozaiq.org/encrypt/ AND http://mozaiq.org/decrypt/