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MULTI-LEVEL AUDIO STEGANOGRAPHY Seminar Guide Presented by 1
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Multi-Level audio steganography

Jan 22, 2018

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Page 1: Multi-Level audio steganography

MULTI-LEVEL AUDIO

STEGANOGRAPHY

Seminar Guide Presented by

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Page 2: Multi-Level audio steganography

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

Page 3: Multi-Level audio steganography

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

Page 4: Multi-Level audio steganography

Evolution

Watermarking

Cryptography

Steganography

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Page 5: Multi-Level audio steganography

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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Page 6: Multi-Level audio steganography

Basic Steganography Model

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Page 7: Multi-Level audio steganography

Encoding

• Prepare cover data

Step1

• Encode embedded data with cover data

Step 2• Steganographic

data

Step 3

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Page 8: Multi-Level audio steganography

Decoding

• Steganographic Data

Step1

• Decode Plain info

Step 2• Embedded

data obtained

Step 3

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Page 9: Multi-Level audio steganography

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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Page 10: Multi-Level audio steganography

Types of Steganography

1. Text/Document Steganography.

2. Image Steganography.

3. Audio Steganography.

4. Network / Protocol Steganography.

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Page 11: Multi-Level audio steganography

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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Page 12: Multi-Level audio steganography

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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Page 13: Multi-Level audio steganography

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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Page 14: Multi-Level audio steganography

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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Page 15: Multi-Level audio steganography

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

Page 16: Multi-Level audio steganography

LSB Encoding & Decoding

Low bit encoder Low bit decoder

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Page 17: Multi-Level audio steganography

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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Page 18: Multi-Level audio steganography

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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Page 19: Multi-Level audio steganography

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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Page 20: Multi-Level audio steganography

Overview of MLS

Mainly there are three permutations for MLS.

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Page 21: Multi-Level audio steganography

Permutation 1

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Page 22: Multi-Level audio steganography

Permutation 2

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Permutation 3

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Page 24: Multi-Level audio steganography

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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Page 25: Multi-Level audio steganography

Before & After Steganography

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Page 26: Multi-Level audio steganography

Comparison with PSNR Graph

This hides three secret messages.

No visible changes in graphs.

Undetectability is achieved

Hence high security.

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Page 27: Multi-Level audio steganography

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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Page 29: Multi-Level audio steganography

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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Page 30: Multi-Level audio steganography

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

Page 31: Multi-Level audio steganography

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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Page 34: Multi-Level audio steganography

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