1. Secret Hiding and Retrieval Techniques for Digital Media 機密訊息在數位媒體中的隱藏及擷取技術之研究
Advisor: Chin-Chen Chang1, 2
Student: Yi-Hui Chen2
1 Dept. of Information Engineering and Computer Science,
Feng Chia University
2 Dept. of Computer Science and Information Engineering,
National Chung Cheng University

2. Outline Part I: Secrets Hiding for Digital Images
Image Steganography
LSB-based High-Capacity Data Embedding Scheme for Images
Part II: Secrets Hiding for Compression Codes
Joint Coding and Embedding Techniques for Multimedia Images

3. Part I : Secrets Hiding for Digital Images
LSB-based High-Capacity Data Embedding Scheme for Images

4. Image Steganography ‧Quality, Capacity and Secrets Secrets Sender
Internet
Sender
‧Steganography
- Prison Problem
‧Quality, Capacity and
Security
Secrets
Receiver

5. Prison Problem
Escape
Alice
Bob
Warden

6. Zhang and Wang’s Method
Hiding capacity
= log2(2n+1)
≒ 2.32

7. Proposed Scheme (1/5)
n = 2
Hiding capacity
= log2(3n)
≒ 3.17

8. Steganography (2/5) n=2 a1 a2 50 51 F(50, 51)=50×1+51×3 mod 9 = 51
S = 3, 2 (0≦ S <3n)
p=(3-5+(9-1)/2) mod 9 =2
p=(2-3+(9-1)/2) mod 9 =3

9. Steganography (3/5) a1 a2 50 51 51 50 1 50+(1) = 51 51+(-1)= 501
50+(1) = 51
51+(-1)= 50
Minus (1)3(1)3
p=2=(02)3
(-11)3
0+(-1)=-1
1+(0)=1
Minus (1)3(1)3
p=3=(10)3
(0 -1)3

10. Steganography (4/5) a1 a2 51 50 1 a1 a2 51 50 11
F(1, 1)=1×1+1×3 mod 9 = 4
p=(2-4+(9-1)/2) mod 9 =2
1+(1)=2
Minus (1)3(1)3
p=2=(02)3
(-1 1)3
1+(-1)=0 a1 a2 51 50 2

11. Steganography (5/5) a1 a2 51 50 2 F(51, 50)=51×1+50×3 mod 9 = 3
F(51, 50)=51×1+50×3 mod 9 = 3
F(0, 1)=2×1+0×3 mod 9 =2

12. Experiments (1/4)
[16] Chang, C. C. and Tseng, H. W., “A Steganographic Method for Digital Images Using Side
Match,” Pattern Recognition Letters, Vol. 25, No. 10, pp , 2004.
[46] Mielikainen, J., “LSB Matching Revisited,” IEEE Signal Processing Letters, Vol. 13,
No. 5, pp , 2006.
[58] Wang, C. M., Wu, N. I., Tsai, C. S. and Hwang, M. S., “A High Quality Steganographic
Method with Pixel-Value Differencing and Modulus Function,” Journal of Systems and
Software, Vol. 81, No. 1, pp , 2008.
[60] Wu, D. C. and Tsai, W. H., “A Steganographic Method for Images by Pixel-Value
Differencing,” Pattern Recognition Letters, Vol. 24, No. 9-10, pp , 2003.

13. Experiments (2/4)
Guillermito, Chi-square Steganography Test Program, available at

14. Experiments (3/3)

15. Experiments (4/4)
p≦0.5
Fridrich, J., Goljan, M. and Du, R., “Detecting LSB Steganography in Color and Gray-Scale Images,” Magazine of IEEE Multimedia, Special Issue on Security, 8(4), pp. 22~28, 2001.

16. Part II : Secret Hiding for Compression Codes
Joint Coding and Embedding Techniques for Multimedia Images

17. Introduction Information hiding Sender Receiver
Compression code: …
Digital Image
Secret data: 011
Reconstructed image
Compression code …
Secret data: 011 17

18. Squared Euclidean distanceVQ
Squared Euclidean distance
Vector Quantization (VQ)
Overview: X i
Reconstructed Image
512

19. Side Match VQ (SMVQ)
Assumption: Neighboring pixel intensities in an image are pretty similar.
Seed Block
Residual Block

20. Codebook (512) State codebook (8)
X = (81, 15, 53, 34, 51,?, ?, ?, 91, ?, ?, ?, 49,?, ?, ?)
Codebook (512)
State codebook (8)

21. Proposed scheme (1/3)
THSMVQ
Bit=0

22. Proposed scheme (2/3)
var(L)+var(U) <THvar
Clustering
result
Bit=0

23. Proposed scheme (3/3)
Clustering result

24. Experiments (1/3)
[9] Chang, C. C. and Wu, W. C., “A Steganographic Method for Hiding Secret Data Using Side Match Vector
Quantization,” IEICE Transactions on Information and Systems, Vol. E88-D, No. 9, pp , Sep
[33] Jo, M., and Kim, H. D., “A Digital Image Watermarking Scheme Based on Vector Quantisation,”
IEICE Transactions on Information and Systems, Vol. E85-D, No. 6, pp , 2002.

25. Scheme-1
Scheme-2

26. Bit rate (0.56 bpp) and the similar capacity (16 kilobits)

27. Further Works Secrets data hiding Other digital media
No extra indicator need to store
Other digital media
Text-based document
Audios

28. Thanks for your attention