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  1. 1. Steganography Presented by: Chudasama Khushbu VIII sem-CSE 10ECACS003 Presentation On
  2. 2. Outlines What is Steganography? History of Steganography Steganography, Cryptography & Watermarking Types of Digital Steganography Image based Technique Security Use of steganography
  3. 3. Greek Words: STEGANOS – “Covered” GRAPHIE – “Writing” Steganography is the art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message. This can be achieve by concealing the existence of information within seemingly harmless carriers or cover Carrier: text, image, video, audio, etc Steganography
  4. 4. Tattoos on shaved heads Wax-covered tablets Microdots – shrunken pictures Invisible Inks - milk, fruit juice, urine History of Steganography
  5. 5. STEGANOGRAPHY TERMS Carrier or Cover File Stego-Medium Embedded or Payload Steganalysis
  6. 6. Security Systems Cryptography Information Hiding Steganography Watermarking Steganography, Cryptography &Watermarking
  7. 7. Major two branches of information hiding, Steganography and Watermarking. Steganography and Cryptography are closely related. The difference is in their goals. Conti..
  8. 8. Cryptography • Science of writing in secret code and is an ancient art. • Achieve security by encoding messages to make them non- readable. • Process to convert Plain Text in to Cipher Text. • Plain Text: Clear Text • Cipher Text: Codified Text Plain Text Cryptogra phy Tech Cipher Text
  9. 9. Watermarking • Used to verify the identity and authenticity of the owner of a digital image. • Process in which the information which verifies the owner is embedded into the digital image or signal. Signals could be either videos or pictures or audios. • Two types; visible watermarking and invisible watermarking.
  10. 10. Steganography How It Works
  11. 11. Main difference is..  Cryptography: although encypted and unreadable,the existence of data is not hidden  Steganography: no knowledge of the existence of the data  Watermarking: extending the file with extra information Conti..
  13. 13. ENCODING Step 3 • Steganographic data Step 2 • Encode embedded data with cover data Step1 • Prepare cover data
  14. 14. DECODING • Steganographic Data Step1 • Decode Plain info Step 2 • Embedded data obtained Step 3
  15. 15. Hiding a Message inside Text Hiding a Message inside Images • Most popular technique Hiding a Message inside Audio and Video Files Types of Steganography
  16. 16. Hiding a Message inside Text  Partially effective  Example: randoM capitalosis is a rarE disEase ofTen contrAcTed by careless inTernet users. tHis sad illnEss causes the aFfected peRsON To randomly capitalize letters in a bOdy oF texT. please do not confuse this disease witH a blatant attEmpt aT steganogRAPhy. Reveals: MEET AT THE FRONT OF THE TRAP
  17. 17. Hiding a Message inside Images  Most widely used medium today.  Takes advantage of our limited visual perception of colors.  This field is expected to continually grow as computer graphics power also grows.
  18. 18. Image Attributes: • Digital images are made up of pixels. • The arrangement of pixels make up the image’s “raster data”. • 8-bit and 24-bit images are common. • The larger the image size, the more information you can hide.
  19. 19. Hiding a Message inside Audio and Video Files • Embedding secret message in to digital sound is known as audio & video steganography. • Large amount of data that can be hidden inside. • Hard to recognize because of the continuous flow of information (moving stream of images and sound).
  20. 20. The most common approaches to information hiding in images are:  Least significant bit (LSB) Insertion  Masking and Filtering Techniques  Algorithms and Transformations Image based Technique
  21. 21.  Least Significant Bit (LSB) Insertion  Most popular technique when dealing with images.  Replaces least significant bits with the message to be encoded.  It is best to use images with “noisy areas” – areas with ample color variation and without large areas of solid color.  Requires on average that only half the bits in image be changed.
  22. 22. Example:  example shows how the letter A can be hidden in the first eight bytes of three pixels in a 24-bit image. Pixels: (00100111 11101001 11001000) (00100111 11001000 11101001) (11001000 00100111 11101001)
  23. 23. A: 10000001 Result: (00100111 11101000 11001000) (00100110 11001000 11101000) (11001000 00100111 11101001)  Only three bits that were actually altered. A only requires eight bytes to hide it in, the ninth byte of the three pixels can be used to hide the next character of the hidden message.
  24. 24.  Masking and Filtering • Uses..  Digital Watermarking – provides identification pertaining to the owner; I.e. license or copyright information - Invisible & Visible  Fingerprinting – provides identification of the user; used to identify and track illegal use of content
  25. 25. Confidentiality: any unauthorized person does not know that sensitive data exists Survivability: verifing that the data does not get destroyed in the transmission No detection: cannot be easily found out that the data is hidden in a given file Visibility: people cannot see any visible changes to the file in which the data is hidden Security
  26. 26. Governments Businesses: Digital Watermarking Individuals Uses of Steganography
  28. 28. U.S. officials said on 5 February 2001 that Late. Osama bin Laden was posting instructions for terrorist activities. He was master in this technology. The 9/11 attack heightened our awareness of steganography. It is well published that Bin Laden and his terrorist cells use steganography for communications
  29. 29. Live Demo:
  30. 30. QUERIES