An efficient reversible image authentication method using improved PVO and LSB substitution techniques Source : Signal Processing: Image Communication, vol. 58, pp. 111-122,  October 2017 Authors : Wien Hong, Meijin Chena and Tung Shou Chen Speaker : Chia-Shuo Shih Date : 2018/12/27 1

Outline Introduction Related work Proposed method Experimental results Conclusions 2

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

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

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

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

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

Proposed method 8 0 0 1 1 1 1 0 AC key: 𝑘 𝑒 60 54 59 63 61 55 58 64 53 65 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 = 00111100 𝑆𝐵 𝐿𝑆𝐵 =0 0 0 1 1 1 1 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

Proposed method 𝑆𝐵 𝐿𝑆𝐵 =0 α 2 = 4 AC = 3( α 𝑖 −1) bits 9 64 66 61 63 62 60 58 59 64 65 67 61 63 62 59 60 57 IPVO AC+SB: 1 0 1 0 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 = 101 + 0 = 1 0 1 0 AC = 101 9

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

Proposed method-Image authentication and recovery 61 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 1 0 1 0 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

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

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

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. 174-185 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. 395-413 Yin Z., Niu X., Zhou Z., Tang J., Luo B. ”Improved reversible image authentication scheme” Cogn. Comput., 8 (5) (2016), pp. 890-899 14

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

Experimental results 16

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

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

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

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

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

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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