MULTI-LEVEL AUDIO STEGANOGRAPHY Seminar Guide Presented by 1
MULTI-LEVEL AUDIO
STEGANOGRAPHY
Seminar Guide Presented by
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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.2
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.3
Evolution
Watermarking
Cryptography
Steganography
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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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Basic Steganography Model
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Encoding
• Prepare cover data
Step1
• Encode embedded data with cover data
Step 2• Steganographic
data
Step 3
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Decoding
• Steganographic Data
Step1
• Decode Plain info
Step 2• Embedded
data obtained
Step 3
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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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Types of Steganography
1. Text/Document Steganography.
2. Image Steganography.
3. Audio Steganography.
4. Network / Protocol Steganography.
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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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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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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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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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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 LSB15
LSB Encoding & Decoding
Low bit encoder Low bit decoder
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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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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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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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Overview of MLS
Mainly there are three permutations for MLS.
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Permutation 1
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Permutation 2
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Permutation 3
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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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Before & After Steganography
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Comparison with PSNR Graph
This hides three secret messages.
No visible changes in graphs.
Undetectability is achieved
Hence high security.
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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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Disadvantages
If the all algorithms are known Leakage occurs.
Password leakage also may occur.
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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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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
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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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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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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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