1. Separable and error-free reversible data hiding in encrypted images
Source：Signal Processing, 2016, 123:9-21.
Authors： DawenXu, RangdingWang
Speaker ：Xiaozhu Xie
Date ： /03/29

2. Outline Scenario Proposed scheme Experimental results Conclusions
I would like to present in these five parts.

3. Scenario
Embed additional messages(e.g.,labels, time stamps, category information etc.)
KEMB
KENC
KENC
[səˈnærioʊ] cloud storage is becoming more and more popular, I bet everyone here uses cloud storage more or less. However the security problem followed. For example, many photos of Hollywood actresses leaked from iCloud two years ago.
So before upload the images, we would like to encrypt it.
And on the server side, cloud server would like to embed some information for management, for example…. So

4. Proposed scheme(1/13) SP
NSP

5. Proposed scheme(2/13)-Generation of interpolation-errorSP
NSP
[23] L.X. Luo, Z.Y.Chen, M.Chen, Reversible image watermarking using interpolation technique, IEEE Trans.Inf.Forensics Secur.5(1)(2010) 187–193.

6. Proposed scheme(3/13)-Generation of interpolation-error90 28 30 … 98
100 32 24 86 90 59 28 29 30 … 98 79 64 48 31 99
100 66 32 61 77 93 65 24 55 86 92 90 1 28 21 30 … -2 16 4 9 98 -1
100
-16 32
-31 19 11 24
-15 86
Original Image
Down-sample pixels
Interpolation
Interpolation-errors 𝐸(𝑖,𝑗)
-127 ~ +127

7. Proposed scheme(4/13)-Image encryption
124 1
245 34 21 … -2 23 7 65 42 -1
154
-45
230
-34 12 43 25
-32
189
SP: Bitwise XOR with random bit stream generated by 𝐾 𝑒𝑛 .
NSP(𝐸(𝑖,𝑗)): As follows.
The encrypted image
( 𝑇 𝑛 =−2, 𝑇 𝑝 =1)
𝐸 ′ 𝑖,𝑗 = 𝐸(𝑖,𝑗) 𝑖𝑓 𝐸(𝑖,𝑗)∈ 𝑇 𝑛 , 𝑇 𝑝 𝑚𝑜𝑑 𝐸 𝑖,𝑗 − 𝑇 𝑝 𝑟 1 𝑖,𝑗 , 127−2 𝑇 𝑝 ( 𝑇 𝑝 +1) 𝑖𝑓 𝐸(𝑖,𝑗)∈ 𝑇 𝑝 +1,127−( 𝑇 𝑝 +1) −𝑚𝑜𝑑 𝑟 2 𝑖,𝑗 − 𝐸 𝑖,𝑗 − 𝑇 𝑛 −1 , 𝑇 𝑛 +( 𝑇 𝑛 −1) 𝑖𝑓 𝐸(𝑖,𝑗)∈ −127−𝑇 𝑛 , 𝑇 𝑛 −1
Random numbers: 𝑟 1 (𝑖,𝑗)∈ 0,127−2( 𝑇 𝑝 +1) , 𝑟 2 (𝑖,𝑗)∈ 0,127+ 𝑇 𝑛 +( 𝑇 𝑝 −1)

8. Proposed scheme(5/13)

9. Proposed scheme(6/13)-Data embedding
124 1
245 34 21 … -2 23 7 65 42 -1
154
-45
230
-34 12 43 25
-32
189
124 3
245 36 21 … -4 25 9 67 42 -2
154
-47
230
-36 14 1 45 27
-34
189
10010
𝑇 𝑛 =−2, 𝑇 𝑝 =1
The encrypted image
The marked encrypted image
𝑤 is the to-be-embedded bit

10. Proposed scheme(7/13)-Data extraction and image recovery

11. Proposed scheme(8/13)-Scheme I (data extraction)
124 3
245 36 21 … -4 25 9 67 42 -2
154
-47
230
-36 14 1 45 27
-34
189
10010
Data extraction:
𝑤 = 𝐸 𝑖,𝑗 𝑚𝑜𝑑 𝐸 𝑖,𝑗 ∈ 2 𝑇 𝑛 , 2 𝑇 𝑝 +1
The marked encrypted image

12. Proposed scheme(9/13)-Scheme I (Image recovery)
124 3
245 36 21 … -4 25 9 67 42 -2
154
-47
230
-36 14 1 45 27
-34
189 1 36 … -2 25 9 67 -1
-47
-36 14 45 27
-34 1 21 … -2 16 4 9 -1
-16
-31 19 11
-15
𝑟 1 𝑖,𝑗
𝑟 2 𝑖,𝑗
The marked encrypted image
𝑋 𝑖,𝑗 ∈𝑆𝑃:⨁ 𝐾 𝑒𝑛
𝑋′(𝑖,𝑗)∈𝑁𝑆𝑃 : interpolation 90 59 28 29 30 … 98 79 64 48 31 99
100 66 32 61 77 93 65 24 55 86 92
𝑋 𝑖,𝑗 = 𝑋 ′ 𝑖,𝑗 +𝐸(𝑖,𝑗).

13. Proposed scheme(10/13)-Scheme I (Image recovery)

14. Proposed scheme(11/13)-Scheme II (Image decryption)
124 3
245 36 21 … -4 25 9 67 42 -2
154
-47
230
-36 14 1 45 27
-34
189 3 23 … -4 18 6 11 -2
-18
-33 21 1 13
-17
𝑟 1 𝑖,𝑗
𝑟 2 𝑖,𝑗
The marked encrypted image
𝑋 𝑖,𝑗 ∈𝑆𝑃:⨁ 𝐾 𝑒𝑛
𝑋′(𝑖,𝑗)∈𝑁𝑆𝑃 : interpolation 90 59 28 29 30 … 98 79 64 48 31 99
100 66 32 61 77 93 65 24 55 86 92 90 62 28 52 30 … 94 97 70 54 42 98
100 48 32 92 86 24 38
The marked decrypted image

15. Proposed scheme(12/13)-Scheme II (Image decryption)

16. Proposed scheme(13/13)-Scheme II (data extraction and image recovery)90 62 28 52 30 … 94 97 70 54 42 98
100 48 32 92 86 24 38 3 23 … -4 18 6 11 -2
-18
-33 21 1 13
-17
10010
The marked decrypted image
𝑋′(𝑖,𝑗)∈𝑁𝑆𝑃 : interpolation 1 21 … -2 16 4 9 -1
-16
-31 19 11
-15 90 59 28 29 30 … 98 79 64 48 31 99
100 66 32 61 77 93 65 24 55 86 92
The original image

17. Experimental results (1/5)

18. Experimental results (2/5)

19. Experimental results (3/5)

20. Experimental results (4/5)

21. Experimental results (5/5)
[20] W.M.Zhang,K.D.Ma,N.H.Yu, Reversibility improved data hiding in encrypted images, Signal Process. 94 (2014) 118–127.
[21]X.C.Cao, L.Du, X.X.Wei, D.M.Meng, X.J.Guo, High capacity reversible data hiding in encrypted images by patch-level sparse representation, IEEE Trans. Cybern., no.99, pp.11.

22. Conclusions Separable.
The hidden data can be extracted either in encrypted or decrypted domain.

23. Thank you!