28Steganography.pptx

What is Steganography?defn:the art and science of hiding information by embedding it in some other data.cryptography-render message unintelligiblesteganography-conceal the existence of the messageSome History 1665-Steganographica,Gaspari Schotti 400 B.C.-writings of Herodotus1870-The Pigeon Post into Paris1499-“Steganographia”,Trithemius -steganography and magic2001-A Beautiful MindLow-tech Methods of Steganography Message hidden Message hidden as Message hidden as Message written in invisible ink ID#etched intoThe cover provides a host for transporting the hidden info.info embed -file extractinfoDigital Steganography HTML message as cover?computer program as cover?network protocol headers white space in text unused space in buffer least significant bits of image slight distortion in sound file“Easter eggs”Easter egg from the SimpsonsIn episode 7F19,Dustin Hoffman supplied the voice for Lisas substitute teacher,but was not credited on screen.Instead,they used the phony name Sam Etic.In the next season(episode 7F24),Michael Jackson supplied the voice for a man in an insane asylum that thought he was Michael Jackson.Due to contractualobligations,they were unable to give Jacksonon-screen credit.Instead,the show credited John Jay Smith,another person that doesnt exist.The egg lies in episode 9F09 when Lisa says,It was the greatest movie Ive ever seen in my life!And you wouldnt believe the celebrities who did cameos.Dustin Hoffman,Michael Jackson.of course they didnt use their real names,but you could tell it was them.Steganography in ImagesTwo types of compression:lossless(gif)lossy(jpeg)Sometimes concealed message inserted as a comment.Sometimes the accuracy of the image is sacrificed slightly.Common ToolsStegoDOSWhite Noise StormS-toolsoutguesssteghideThree Types of Steganography1)Covert Channelconceal message so only sender and recipient knowWatermarkingconcealed message contains its source ID 2)_ Watermarkingdesigned for concealed message to survive 3)(Semi-)_ Watermarkingdesigned so concealment is corrupted wheneverstego-file is modified.Applications of SteganographyCovert exchange of informationEstablish identityCombat illegal copyingSteg_How would you?Comparison of files for statistical differencesWhat files are available?