1. An efficient reversible image authentication method using improved PVO and LSB substitution techniques
Source : Signal Processing: Image Communication, vol. 58, pp ,  October 2017
Authors : Wien Hong, Meijin Chena and Tung Shou Chen
Speaker : Chia-Shuo Shih
Date : 2018/12/27 1

2. Outline Introduction Related work Proposed method Experimental results
Conclusions 2

3. Introduction-Reversible Image Authentication
Authentication Code
Original Image
Stego Image
Authentication Code + Recovery Code
Original Image
Stego Image 3

4. Related work-Improved Pixel Value Ordering(IPVO)
PVO: d = 1
IPVO: d = 0 or 1
max 𝑥 ′ =𝑥 𝑖𝑓 𝑑=0 𝑥 ′ =𝑥+𝑏 𝑖𝑓𝑑=1 𝑥 ′ =𝑥+1 𝑖𝑓𝑑>1
min 𝑥 ′ =𝑥 𝑖𝑓 𝑑=0 𝑥 ′ =𝑥−𝑏 𝑖𝑓𝑑=1 𝑥 ′ =𝑥−1 𝑖𝑓𝑑>1
max 𝑥 ′ =𝑥+𝑏 𝑖𝑓 𝑑=1 𝑥 ′ =𝑥+1 𝑖𝑓 𝑑>1 𝑥 ′ =𝑥+𝑏 𝑖𝑓 𝑑=0 𝑥 ′ =𝑥+1 𝑖𝑓 𝑑<0
min 𝑥 ′ =𝑥−𝑏 𝑖𝑓 𝑑=1 𝑥 ′ =𝑥−1 𝑖𝑓 𝑑>1 𝑥 ′ =𝑥−𝑏 𝑖𝑓 𝑑=0 𝑥 ′ =𝑥−1 𝑖𝑓 𝑑<0 4

5. Related work-Improved Pixel Value Ordering(IPVO)
max 𝑥 ′ =𝑥+𝑏 𝑖𝑓 𝑑=1 𝑥 ′ =𝑥+1 𝑖𝑓 𝑑>1 𝑥 ′ =𝑥+𝑏 𝑖𝑓 𝑑=0 𝑥 ′ =𝑥+1 𝑖𝑓 𝑑<0
min 𝑥 ′ =𝑥−𝑏 𝑖𝑓 𝑑=1 𝑥 ′ =𝑥−1 𝑖𝑓 𝑑>1 𝑥 ′ =𝑥−𝑏 𝑖𝑓 𝑑=0 𝑥 ′ =𝑥−1 𝑖𝑓 𝑑<0 5

6. Proposed method 6 IPVO Authentication Code LSB Authentication Code
Original Image
Stego Image 6

7. Proposed method 60 54 59 63 64 66 61 55 62 58 53 65
B 1
B 2
Original Image 60 54 59 63 61 55 58 64 53 65
𝐵 1 1 ={54,59,60,61}
𝐵 1 2 ={55,59,59,63}
𝐵 1 3 ={54,55,58,64}
𝐵 1 4 ={53,60,63,65} 64 66 61 63 62 60 58 59
𝐵 2 1 ={62,63,64,64}
𝐵 2 2 ={60,61,61,66}
𝐵 2 3 ={59,59,60,61}
𝐵 2 4 ={58,60,61,64}
α 1 = 0
α 2 = 4
B 1
B 2
IPVO: d = 0 or 1 7

8. Proposed method 8 0 0 1 1 1 1 0 AC key: 𝑘 𝑒 60 54 59 63 61 55 58 64 5365 60 53 59 64 62 54 58 65 63 55 52 66 60 51 59 64 54 58 65 63 53 55 52 66 61 51 59 64 54 58 65 60 63 53 55 52 66
IPVO
B 1
60 = 𝑆𝐵 𝐿𝑆𝐵 =0 AC 59 64 54 58 65 60 63 53 55 52 66
MD5
 location information (1,1) 
128-bit hash value
Use XOR to 1 bit
AC = 1 8

9. Proposed method 𝑆𝐵 𝐿𝑆𝐵 =0 α 2 = 4 AC = 3( α 𝑖 −1) bits 9 64 66 61 6362 60 58 59 64 65 67 61 63 62 59 60 57
IPVO
AC+SB:
B 2
Stego Image
𝐵 2 1 ={62,63,64,64}
𝐵 2 2 ={60,61,61,66}
𝐵 2 3 ={59,59,60,61}
𝐵 2 4 ={58,60,61,64} 64 61 63 60 59
MD5
128-bit hash value
 location information (1,2) 
Use XOR to 3 bits
AC + 𝑆𝐵 𝐿𝑆𝐵 = =
AC = 101 9

10. Proposed method 60 54 59 63 64 66 61 55 62 58 53 65 61 51 59 64 65 67 54 63 62 58 60 57 53 55 52 66
Original Block
Stego Block 10

11. Proposed method-Image authentication and recovery61 51 59 64 65 67 54 63 62 58 60 57 53 55 52 66
B 1 = α 1 = 0
B 2 = α 2 = 4 64 65 67 61 63 62 59 60 57 64 66 61 63 62 60 58 59
IPVO
Original Block 64 61 63 60 59
Use XOR to 3 bits
MD5
 location information (1,2) 
128-bit hash value
AC = 101 11

12. Proposed method-Image authentication and recovery
key: 𝑘 𝑒 61 51 59 64 54 58 65 60 63 53 55 52 66 60 54 59 63 61 55 58 64 53 65
𝑆𝐵 𝐿𝑆𝐵 =0
IPVO 59 64 54 58 65 60 63 53 55 52 66
MD5
 location information (1,1) 
128-bit hash value
Use XOR to 1 bit
AC = 1 12

13. Experimental results 13 α Lena Peppers Boat Jet Splash Elaine Average
2243
2561
3583
1795
739
4007
2488 1
3478
4580
4971
2550
2134
5439
3859 2
3716
4263
4016
2592
3346
3775
3618 3
3046
2897
2261
2520
3536
1742
2667 4
2026
1429
1023
2252
2821
751
1717 5
1139
522
368
1835
1704
361
988 6
439
118
124
1398
1047
152
546 7
144 12 37
900
650 47
298 8
153
542
407
110
203
 Number of the blocks under various α 13

14. Experimental results
Lo and Hu
Nguyen et al.
Yin et al.
Proposed
Embedding technique HS
PEE
IPVO
Embedded data
AC only
AC and recovery data
Reversibility
Yes
Implementation of location map No
Protection of un-embeddable block
Detectability of equal modification in brightness
Comparisons of the proposed method with other related works.
Lo C.C., Hu Y.C. ”A novel reversible image authentication scheme for digital images” Signal Process., 98 (2014), pp. 
Nguyen T.S., Chang C.C., Shih T.H. “A high-quality reversible image authentication scheme based on adaptive PEE for digital images” KSII Trans. Internet Inf. Syst., 10 (1) (2016), pp. 
Yin Z., Niu X., Zhou Z., Tang J., Luo B. ”Improved reversible image authentication scheme” Cogn. Comput., 8 (5) (2016), pp.  14

15. Experimental results 15 Image Lo and Hu Nguyen et al. Yin et al.
Proposed
Lena
48.75
42.67
51.83
50.48
Peppers
48.70
42.18
51.68
50.24
Boat
48.64
41.95
51.61
49.79
Jet
48.94
43.57
52.11
50.88
Splash
48.92
43.60
52.14
51.41
Elaine
48.65
41.83
51.58
49.61
Average
48.77
42.63
51.82
50.40
The PSNR comparisons of related works. 15

16. Experimental results 16

17. Experimental results 17 Lo and Hu’s method, ER = 0.274
Nguyen et al.’s method, ER = 0.186
Yin et al.’s method, ER = 0.300
 Proposed method, ER =0.105 17

18. Experimental results Detection result: True Detection result: False
Second-stage detection: 18

19. Experimental results 19 Image Lo and Hu Nguyen et al. Yin et al.
Proposed
Lena
0.274
0.186
0.300
0.105
Peppers
0.469
0.225
0.292
0.107
Boat
0.290
0.223
0.308
0.128
Jet
0.381
0.349
0.065
Splash
0.324
0.209
0.262
0.071
Elaine
0.284
0.201
0.286
0.097
Average
0.337
0.212
0.096
Comparisons of error rates. 19

20. Experimental results 20 Lo and Hu ER = 0.870 Proposed ER = 0.201
Nguyen et al. ER = 0.818
Yin et al. ER = 0.884 20

21. Experimental results 21 Lo and Hu’s method Proposed method
Nguyen et al.’s method
Yin et al.’s method 21

22. Conclusions
The proposed method embeds the hashed value of block features.
The proposed method also embeds one bit AC into all un-embeddable blocks. 22

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