steganography full report

[seminar class]

Presented By:
POOJA YADAV

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STEGANOGRAPHY
Steganography - Definition
Steganography
– from the Greek word steganos meaning “covered”
– and the Greek word graphie meaning “writing”
• Steganography is the process of hiding of a secret message within an ordinary message and extracting it at its destination
Modern digital steganography
– data is encrypted
– then inserted and hidden, using a special algorithm which may add and/or modify the contents of the file
– This technique may simply append the data to the file, or disperse it
 Text Steganography
 Image Steganography
 Audio Steganography
 Video Steganography
• Audio and Image Steganography
• Steganography – Modern Day
• Steganography - Tools
Steganography Tools
• Steganos
• S-Tools (GIF, JPEG)
• StegHide (WAV, BMP)
• Invisible Secrets (JPEG)
• JPHide
Steganalysis - Definition
Definition
– Identifying the existence of a message
– Not extracting the message
– Note: Technically, Steganography deals with the concealment of a message, not the encryption of it
– Steganalysis essentially deals with the detection of hidden content
Steganalysis
• By identifying the existence of a hidden message, perhaps we can identify the tools used to hide it.
• If we identify the tool, perhaps we can use that tool to extract the original message.
• Steganalysis – Hiding Techniques
• Common hiding techniques
Appended to a file
 Hidden in the unused header portion of the file near the beginning of the file contents
 An algorithm is used to disperse the hidden message throughout the file
• Modification of LSB (Least Significant Bit)
• Steganalysis – Methods of Detection
Methods of detecting the use of Steganography
– Visual Detection (JPEG, BMP, GIF, etc.)
– Audible Detection (WAV, MPEG, etc.)
– Statistical Detection (changes in patterns of the pixels or LSB – Least Significant Bit) or Histogram Analysis
– Structural Detection - View file properties/contents
• size difference
• date/time difference
• contents – modifications
• checksum
– Steganalysis – Methods of Detection
• Goal
– Accuracy
– Consistency
– Minimize false-positives
– Applications
 Confidential Communication
• Secret Data storing
• Protection Of Data Alteration
• Anomaly – Visual Detection
• Detecting Steganography by viewing it
• Can you see a difference in these two pictures? (I can’t!)
• Steganalysis meets Cryptanalysis
Cryptanalysis
• In Steganography the goal is to hide the message, NOT encrypt it
• Cryptography provides the means to encrypt the message.
• Identify program used to hide message
• Identify the location of the program signature in the file
• Identify the location of the password in the file
• Identify location of the hidden message in the file
• Identify the algorithm used to encrypt the hidden message
ENCRYPTION ALGORITHMS
 XOR
 DES
 AES
Future Scope
• Due to time and computing limitation we could not explore all facts of steganography and detectation techniques.
• We studied the power in our images to test for hidden data.
• Adding hidden data adds random noise