A seminar presentation slide on audio steganography.

1. MULTI-LEVEL AUDIO
STEGANOGRAPHY
Seminar Guide Presented by
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2. Overview
 Steganography.
 Evolution.
 Basic Steganography Model.
 Encoding & Decoding.
 Related Works.
 Steganography Terms.
 Types of Steganography.
 Study of Multi-Level audio steganography.
 Future Scope.
 Conclusion.
 References.
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3. Steganography
 Comes from Greek
- steganos = “covered”
- graphei = “writing”
 Also known as “covered writing”.
 Deals with hiding communicated data.
 Hiding one piece of data within another.
 Only recipient can identify the data using key.
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4. Evolution
Watermarking
Cryptography
Steganography
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5. Related Work
 Multi-Level Steganographic Algorithm for Audio
Steganography using LSB Modification .
 Multi-Level Steganography which defines a new concept
for hidden communication in telecommunication
networks .
 Audio Steganography using LSB Modification and Parity
Encoding Technique.
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6. Basic Steganography Model
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7. Encoding
• Prepare
cover data
Step1
• Encode
embedded
data with cover
data
Step 2
• Steganographic
data
Step 3
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8. Decoding
• Steganographic
Data
Step1
• Decode
Plain info
Step 2
• Embedded
data
obtained
Step 3
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9. Steganography Terms
 Carrier or Cover File - Original message is hidden
inside it .
 Stego-Medium - Medium in which the information is
hidden.
 Embedded or Payload - Information which is to be
hidden or concealed.
 Steganalysis - Process of detecting hidden information
inside a file.
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10. Types of Steganography
1. Text/Document Steganography.
2. Image Steganography.
3. Audio Steganography.
4. Network / Protocol Steganography.
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11. Text/Document Steganography
 The “carrier” is a text document.
 Data is hidden behind every nth letter.
 Three methods
1. Format based Method.
2. Random and statistical Method.
3. Linguistics Method.
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12. Image Steganography
 Cover object is an Image.
 Pixel intensities are used.
 Three methods
1. Least Significant Bit Insertion.
2. Static Parsing Steganography(SPS).
3. Masking and Filtering.
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13. Network / Protocol Steganography
 Hiding with the help of network protocols
 Example cover objects are :
TCP, ICMP, IP etc
 OSI layer network model can be used.
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14. Audio Steganography
 Embedding secret messages into digital sound.
 WAV, AU, and MP3 sound files can be used.
 Human auditory system (HAS) are exploited.
 Methods of audio steganography are :
1. LSB coding .
2. Parity coding .
3. Phase coding.
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15. LSB Coding
 LSB bit is used for data embedding.
 Using LSB increases the capacity
 And decreases the transparency.
 Advantages are :
- Low computational complexity
- Easier Implementation
- Variation in choosing LSB
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16. LSB Encoding & Decoding
 Low bit encoder  Low bit decoder
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17. Parity Coding
 Encode message in the parity bit region.
 Signal break down into separate region.
 Flipping to LSB is possible.
 Advantage :
- Sender has more of a choice in encoding.
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18. Phase Coding
• HAS can’t recognize the phase change in audio signal.
• Encode phase of an audio segment with a data .
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19. Multi-Level Steganography(MLS)
 Combination of two or more steganography methods.
 Consist of three levels :
1. Upper Level.
2. Middle Level.
3. Lower Level.
 Layering approach is used.
 Three messages can be transmitted .
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20. Overview of MLS
 Mainly there are three permutations for MLS.
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21. Permutation 1
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22. Permutation 2
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23. Permutation 3
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24. Multi-Level Steganography(MSL)
 Stego audios is compared with PSNR graph.
 With help of two equations -
1. Mean Squared Error (MSE):
2. Peak Signal-to-Noise Ratio (PSNR):
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25. Before & After Steganography
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26. Comparison with PSNR Graph
 This hides three secret messages.
 No visible changes in graphs.
 Undetectability is achieved
 Hence high security.
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27. Advantages
 Potential capability to hide existence of data.
 Hardness of detecting the hidden (i.e., embedded) data.
 Strengthening of the security of the encrypted data.
 Maintain clarity of audio signal.
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28. Disadvantages
 If the all algorithms are known Leakage occurs.
 Password leakage also may occur.
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29.  Confidential communication and secret data storing.
 Protection of data alteration.
 Access control system for digital content distribution.
 Media Database systems.
 Use by intelligence services.
Applications
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30. Cryptography vs. Steganography
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 The difference is in their goals...
- Cryptography: although encypted and unreadable, the existence
of data is not hidden.
- Steganography: no knowledge of the existence of the data .
Cryptography
cryptos
hidden
graphia
writing
Steganography
steganos graphia
covered writing

31. Watermarking vs. Steganography
 Goal of steganography
– Intruder cannot detect a message
 Goal of watermarking
– Intruder cannot remove or replace the message
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32. Future Scope
 Further we can extend this approach by combining any
four techniques or more.
 By combining more techniques we can increase capacity
 The system becomes more secure towards detection.
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33. Conclusion
 Based on three different techniques.
 Technique for hiding text data into digital audio files .
 Three secret messages can be hidden.
 Uses three traditional method of steganography
 Level based approach to reach the goal.
 The output stego object is very difficult to decode .
 Which makes this method successful in the world.
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34. Reference
[1] Jasleen Kour, Deepankar Verma “ Steganography Techniques –A Review Paper “
Volume-3, Issue-5 ,2014
[2] Ramandeep Kaur ,Jagriti Bhatia ,Hardeep Singh,Rajesh Kumar
“Multilevel Technique to Improve PSNR and MSE in Audio Steganography “
Volume 103 – No.5, October 2014
[3] Nitasha, Nidhi Sood” Enhancing the Security of Multilevel Audio
Steganography” May - 2014
[4] Prof. Samir Kumar Bandyopadhyay and Barnali Gupta Banik: “Multi-Level
Steganographic Algorithm for Audio Steganography using LSB Modification
and Parity Encoding Technique”, Volume 1, Issue 2, July – August 2012.
[5] “audio steg: methods”, Internet publication on
http://www.snotmonkey.com/work/school/405/methods.html
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QUERIES