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Steganography ppt

Apr 13, 2017



Taha Malampatti
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  • TOPIC:

    STEGANOGRAPHYPrepared by:Shruti Ghelani-140050107031Taha Malampattiwala-140050107052Jinal Mayavanshi-140050107056

  • INFORMATION HIDINGInformation Hiding is a branch of computer science that deals with concealing the existence of a messageIt is related to cryptography whose intent is to render messages unreadable except by the intended recipientsIt employs technologies from numerous science disciplines:Digital Signal Processing (Images, Audio, Video)CryptographyInformation Theory\Coding TheoryData CompressionHuman Visual/Auditory perceptionThere are four primary sub-disciplines of Information HidingSteganographyWatermarkingCovert ChannelsAnonymity

  • Alice and BobClassical names given to the parties wishing to communicateSometimes, you may have a Carol and a DaveEve, an adversary, can listen to but not modify or forge a message(think passive eavesdropping)Wendy the Warden, another adversary, can monitor, modify, or forge a messageA passive warden simply listens (like Eve)An active warden may modify a messageA malicious warden may forge a fake message


  • 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 message


  • Steganography literally means covered writingA stegosaurus has a covered backSteganographys primary goal is to hide data within some other data such that the hidden data cannot be detected even if it is being soughtSecondary goals:prevent extraction from the cover file without destroying the coverprevent destruction of the stego-message without destroying the coverMost frequently, steganography is applied to images, but many other data or file types are possibleAudioVideoTextExecutable programs

  • The cover provides a host for transporting the hidden


  • Digital 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


  • 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 ToolsStegoDOS

    White Noise Storm





  • APPLICATIONS OF INFORMATION HIDINGCovert military communicationsCovert police communicationsCriminals have learned that police are nearby when they hear encrypted communications, so they abate their activity for the momentA steganographic system would prevent this detectionDigital Rights Management protecting intellectual property such as images, music, electronic books, etc.Embedding textual data in medical images would better ensure that the picture belongs to a particular patientThis technique could apply to personal pictures, sounds, and moviesTamper proofing ensuring a data file has not been changedCommunicating in an oppressive country w/o free speech

  • NEFARIOUS APPLICATIONS OF INFORMATION HIDINGYou wont find these applications in the bookmoney launderingdrug runningchild pornographyspying (good or bad depending upon which side youre on!)terrorismUnfortunately, these uses are also possibleThe technology itself isnt bad, but like many things, it can be (and is) abusedSince there are nefarious uses, law enforcement and the military is also interested in understanding hiding techniques and detecting hidden dataThere are some projects right here at UTSA that have done research for the Air Force

  • STEGANALYSISSteganalysis is the detection of data that has been hiddenIt is a cat and mouse game as one group of researchers come up with better ways to hide stuff, another group figures out how to detect it or perhaps just destroy itIn the summer course last year, one student thought he had a hiding system that was undetectableHis lab partner wrote a statistical analysis program that exposed the hidden messageThe first student modified his program to defeat the attackHis lab partner modified his analyzer and still found the message