The document presents a seminar on dual-layer security for data using LSB image steganography and AES encryption. It outlines the problem of data security in communication, the methodology involved in embedding secret messages in images, and the implementation details using Java. The seminar concludes with a discussion on the advantages, applications, and future prospects of this security approach.

1. Seminar
On
Dual Layer Security Of Data Using LSB Image
Steganography Method And AES Encryption Algorithm
Presented By:
Bikash Chandra Prusty
Reg. No. : 1301227584
Department of Electronics and Telecommunication Engineering
C. V. Raman College Of Engineering, Bhubaneswar

2. Outline
1. Problem Statement
2. Motivation
3. Introduction
4. Steganography Layer
5. Encryption/Decryption Layer
6. LSB Image Steganography Algorithm
7. Implementation
8. Comparison Between Cover Image, Stego And Encrypted Stego Image
9. Advantages
10. Applications
11. Conclusion
12. Future Prospects
13. References
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3. Problem Statement
In today’s scenario security of data is a very big challenge in any communication. The Digital
Image Steganography is the science of hiding sensitive information in another transmission
medium to achieve secure and secret communication.
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4. Motivation
 To limit unauthorized access and provide better security during message transmission
 To embed data or secret message in a digital image by the application of a suitable encryption and
decryption algorithm
 To hide the existence of communication
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5. Introduction
LSB Image Steganography
 The word “Steganography” is a Greek word which means “covered or hidden writing”
 In other words Steganography is a technique of hiding information behind the covered medium
 The main motive of Steganography is to hide the existence of communication
 Image Steganography requires following elements to carry out the work:
• Cover Medium: It is an image that holds secret message
• The Secret Message: It is the message to be transmitted. It can be plain or encrypted text
• The Stego-Key: It is the key used to hide message
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6. Introduction (contd.)
Advance Encryption Standard (AES-128 bits)
 Advanced Encryption Standard (AES), also known as Rijindael is used for securing information
 AES is a symmetric block cipher that is used with key length of 128-bits
 High security, mathematical soundness, resistance to all known attacks, high encryption speed
are some of the characteristics of AES algorithm
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7. Introduction (contd.)
Figure 1. Basic Structure of AES 128 Bit Algorithm
 The basic structure of AES is shown in Figure 1
 AES Algorithm consists of mainly four transformations, namely:
• SubBytes: In this transformation S-Box is used to perform byte by
byte substitution of the block resulting in nonlinearity in cipher
•ShiftRows: This transformation is performed on rows of the states by
keeping first row unchanged but changing second, third and forth row by
cyclic one byte , two byte and three byte shift respectively
•MixColumns: Each value in the column is multiplied with against each
row value of a standard matrix. The result of this multiplication are
XORed together
•AddRoundKey: Round key which is derived from a cipher key using a
key schedule is combined with each byte of the state using XOR
operation
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8. Steganography Layer
 In this process two inputs are provided to the LSB steganography algorithm.First input is the cover
image in which secret message is embedded and second is secret message itself
 Output of this process is Stego Image (image with secret message)
 Figure 2(a) shows embedding and encryption process
Figure 2. (a) Embedding and Encryption Process
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9. Encryption/Decryption Layer
 In this layer the stego image is encrypted using AES algorithm
 At the receiver end reverse process is applied by decrypting the stego image
 Figure 2(b) depicts how message extraction and decryption is done
Figure 2. (b) Extraction and Decryption Process
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10. LSB Image Steganography Algorithm
• S(i,j) = C(i,j) - 1, if LSB(C(i,j)) = 1 and SM = 0
• S(i,j) = C(i,j) + 1, if LSB(C(i,j)) = 0 and SM = 1
• S(i,j) = C(i,j), if LSB(C(i,j)) = SM
Where LSB(C(i,j) stands for the LSB of cover image C(i,j) and “SM” is the next message bit to be
Encoded and S(i,j) is the stego image
Example:
Pixels before Embedding: Pixels after Embedding “1010011”, i.e., alphabet “S”
using LSB Algorithm:
Pixel 1: 10001100 01001111 00001111 Pixel 1: 10001101 01001110 00001111
Pixel 2: 01010100 11010101 11011010 Pixel 2: 01010100 11010100 11011011
Pixel 3: 11101000 11110110 10000001 Pixel 3: 11101001 11110110 10000001
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11. Implementation
 The dual layer security of data using LSB and AES is implemented in JAVA programming using
NetBeans IDE due to its flexibility and robustness
 Application starts its work with steganography layer by asking cover media i.e. RGB image in
which secret message is to be embedded and the secret message itself
 Each RGB image has three color components (Red, Green, and Blue) each of which is 8 bits. So
data is hidden in every least significant bit of each color component to achieve steganography
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12. Implementation (contd.)
Enbedding Data Using LSB Embedding
Process
 The implementation interface is shown in Figure 3
 In Figure 3 cover image is the original image and after
embedding the message, it is shown on right hand side
of the interface under the stego image block
 Both the images look similar but the stego image has
that secret message embedded in it
Figure 3. Steganography Layer (Embedding
Process)
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13. Implementation (contd.)
Encrypting/Decrypting Stego Image
 Stego image and 16 characters (128 bits) encryption key is given as input to this layer and the
output of this layer is encrypted stego image
 At the receiver end the user uses same 128 bit encryption key to decrypt the stego image
 The stego image is then provided to steganography layer to get the desired secret message
 Figure 4 shows the Encryption/Decryption Layer
Figure 4. Encryption/Decryption Layer
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14. Implementation (contd.)
Extraction Process
 The process starts with providing the
decrypted stego image to the system
 Figure 5 shows the interface of the system
used for extraction process
 After clicking on decode button user will get
the desired secret message
Figure 5. Steganography Layer (Extraction Process)
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15. Comparison Between Cover Image,
Stego And Encrypted Stego Image
 There is no difference between the stego and cover image as shown in Figure 6(a) and 6(b)
 Changes in images are done at pixel level that is almost unnoticeable which leads to high security
 After the encryption of stego image, it becomes encrypted as shown in Figure 6(c)
(a) (b) (c)
Figure 6. (a) Cover Image (b) Stego image (c) Encrypted Stego Image
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16. Advantages
 Intruder cannot detect a message
 Simple to implement
 Existence of communication is hidden
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17. Applications
 Smart IDs (identity cards) where individuals’ details are embedded in their photographs
 Media database systems
 Confidential communication and secret data storing
 In modern printers
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18. Conclusion
 Both steganography and cryptography are combined together to achieve desired results
 For image steganography, simplest yet effective method called LSB image steganography
algorithm is used
 For encryption/decryption layer AES encryption algorithm is used
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19. Future Prospects
 Enhancing the current LSB algorithm for modifying the steganography layer
 Applying other steganography techniques to improve upon the results
 Test with other symmetric and asymmetric key encryption algorithm
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20. References
[1] Satwinder Singh and Varinder Kaur Attri, ” Dual Layer Security of data using LSB Image Steganography
Method and AES Encryption Algorithm”, International Journal of Signal Processing, Image Processing
and Pattern Recognition, vol. 8, no. 5, (2015).
[2] N. A. Al-Otaibi and A. A. Gutub, “2-Leyer Security System for Hiding Sensitive Text Data on
Personal Computers”, Lecture Notes on Information Theory, vol. 2, no. 2, (2014).
[3] S. Gupta, G. Gujral and N. Aggarwal, “Enhanced Least Significant Bit Algorithm for Image
Steganography”, International Journal of Computational Engineering & Management, vol. 15 no. 4,
(2012).
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