Image authentication and tamper detection using fragile watermarking in spatial domain

Transcription

1 International Journal of Advanced Reearch in Computer Engineering & Technology (IJARCET) Volume 6, Iue 7, July 2017, ISSN: Image authentication and tamper detection uing fragile watermarking in patial domain Yadwinder Kaur, Dr. Sukhjeet Kaur Ranade Abtract In thi paper a fragile watermarking cheme baed on adaptive embedding rule i propoed. The watermark embedding and detection rule are applied according to the characteritic of image block. In our algorithm we have ued gray level variance of image block to ditinguih it a mooth and unmooth block. The dicrete embedding rule are applied for mooth and unmooth block to improve authentication of the image. In order to acce the performance of the propoed cheme copy and pate attack ha been applied to the watermarked image. Experimental reult have been compared with Hu and Tu [9] method and found ignificant increae in PSNR of the watermarked image and decreae in Fale negative rate and Fale poitive rate. Index Term Fragile watermarking, Image authentication, Spatial domain, Tamper detection. I. INTRODUCTION Due to rapid growth of internet and digital technologie, the digital image can be eaily hared acro the globe. At the ame time, the data hared can be eaily manipulated with the help of image proceing tool uch a Photohop. The eae and extent of uch manipulation draw the attention to the need of image authentication. Therefore, verifying the integrity of digital image ha become a crucial reearch topic. Image authentication can be implemented uing digital ignature or digital watermarking. A digital ignature i an encrypted or igned hah value of image content. A digital ignature can detect that an image i modified but it drawback i that it cannot locate the tampered region. Digital watermarking enable not only identifying whether an image i tampered, but alo locate the tampered part. Thu digital watermarking overcome the limitation of digital ignature. Digital watermark baed authentication cheme ha two tep: the firt i embedding of the watermark and the econd i tamper detection. The digital watermarking cheme not only identify whether an image i tampered, but can alo locate the tampered part. In digital watermarking fragile watermarking i ued for the purpoe of authentication of the image. Fragile watermarking can be applied in patial domain or tranform domain. In patial domain the intenity value of the pixel are modified directly to embed the watermark. In cae of the tranform Manucript received July, Yadwinder Kaur, Department of Computer Science, Punjabi Univerity Patiala, India. Dr. Sukhjeet Kaur Ranade, Aociate Profeor, Department of Computer Science, Punjabi Univerity Patiala, India. domain the tranform coefficient of the image are modified to embed the watermark. We have choen to work in patial domain a it i eay to implement and it computational complexity i le. II. LITERATURE SURVEY The firt fragile watermarking technique wa propoed by Walton [1] in 1995 baed on the ue of the checkum which i calculated from the 7 mot ignificant bit and embedded in the leat ignificant bit. It ha a limitation that one can change the image content by keeping the leat ignificant bit unchanged and it cannot detect the tamper location. Yeung and Mintzer [2] propoed an algorithm to verify that an image i not modified by the ue of an inviible watermark embedded into the image pixel value. The watermark extraction proce extract the embedded watermark from watermarked image uing the verification key. The limitation of thi technique i that watermark can be eaily forged. Kailaanathan [3] propoed a modified verion of the Yeung Mintzer cheme in order to prevent the two main attack propoed for Yeung Mintzer method. Lee and Lin [4] propoed a cheme that ue the dual watermark for the purpoe of the image tamper detection and recovery. In propoed cheme every block in the image contain watermark of further two block. For every non-overlapping block in the image there are two copie of watermark. Therefore there are two copie of watermark for the entire image and when firt copy i detroyed the econd watermark can be ued. A ecret key that i end along with the watermarked image i ued to extract the watermark for tamper recovery purpoe. Zhang and Wang [5] propoed a method baed upon novel fragile watermarking which can recover the original image from the tampered image. In thi cheme a watermark which conit of reference bit and check bit i embedded into the original image uing data hiding method. In order to find the tampered image block the extracted bit can be compared with the calculated check bit. The diadvantage of thi technique i that it cannot recover the tampered part if the tampered area i large. Rawat and Raman [6] dicued a novel chao baed watermarking algorithm for image authentication and. All Right Reerved 2017 IJARCET 1058

2 International Journal of Advanced Reearch in Computer Engineering & Technology (IJARCET) Volume 6, Iue 7, July 2017, ISSN: tamper detection. The propoed method can detect any change made to the image and can alo how the pecific location that have been changed. Two chaotic map are ued to improve the ecurity of the propoed cheme. In thi cheme the initial value of the chaotic map are ued a ecret key. In order to extract the right watermark the peron hould have the correct key. The cheme ha two limitation firt the cat map that i ued to diarrange the hot image i appropriate only for quare image. Second it cannot reit collage attack. Teng et al [7] propoed the cheme that analyzed the ecurity of a chaotic ytem baed fragile watermarking cheme for image tamper detection propoed by Rawat and Raman [6].The propoed method dicued ome error and modification attack againt Rawat and Raman cheme. The experimental reult and theoretical analyi howed that the fragile watermarking cheme of Rawat i not ecure. Thi method propoed an improved verion in order to improve the ecurity of the exiting technique. Performance evaluation i carried out by performing the attack uch a cut and pate attack, text addition and collage attack. Caragata et al [8] propoed two attack on Teng et al [7] fragile watermarking cheme. The attacker can apply valid watermark on tampered image in both the cae, therefore making the watermarking cheme uele. The firt attack ue the watermarked verion of two choen image, and the econd attack i a generalization of the firt, ue a number of arbitrary watermarked image. The paper alo model the cryptanalyi proce for the econd attack uing Markov chain in order to demontrate that the neceary number of image i relatively mall for a high probability of ucceful attack. All the reult that are preented in thi paper have been confirmed by a practical implementation. Hu and Tu [9] propoed the cheme that ue the moothne to differentiate the type of image block and ue different watermark embedding, tamper detection, and recovery cheme for different block type. The performance of thi cheme can be improved further by changing it embedding rule and tamper detection procedure. III. PROPOSED METHOD In thi work the embedding and tamper detection procedure of the exiting cheme [9] i modified in order to improve it efficiency. In the propoed cheme the watermark embedding rule are defined according to the characteritic of image block. The gray level variance of image block i ued to ditinguih it a mooth and unmooth block. The patial domain layout of non mooth and mooth mall block are hown in Fig.1 and Fig.2 repectively, where each row repreent eight bit b 7, b 6,..., b 0 of a pixel. A i the authentication information of a mall block, R i the recovery information of a mall block, R l i the recovery information of a large block, M i the two bit information obtained from the two mot ignificant bit of the mean of each mall block. b 7 b 6 b 5 b 4 b 3 b 2 b 1 b 0 p 0 p 1 p 2 p 3 A A A R l Fig. 1 Watermark embedding rule for unmooth mall block A A M M b 7 b 6 b 5 b 4 b 3 b 2 b 1 b 0 R R A R A A R A M R R l M Fig. 2 Watermark embedding rule for mooth mall block The watermarking embedding and tamper detection procedure i decribed in detail a follow: Watermark embedding procedure: 1. Divide the entire image into k = M N/64 non-overlapping large block of 8 8. Each large block conit of 16 mall block of 2 2. M and N are height and width of image repectively. 2. Compute gray level variance of each large block and ort it in decending order. The top (M N/)/ (64 3) block are non-mooth block and the remaining are mooth block. 3. Iterate for each large block a) Compute the mean of the large block and convert it in the binary form and then generate the 16 bit information by producing combination of firt four mot ignificant bit four time and then mot ignificant bit. Embed thee 16 bit in R l poition of 16 mall block. b) Calculate the mean of each 2 2 non-mooth mall block and convert it into binary form. Embed the five mot ignificant bit of the mean in R poition. c) If the current block i the lat block then proceed to tep 4 ele go to tep 3 (a). 4. In order to minimize the difference between the watermarked image and original image the following equation i ued a moothing function. where x i the value of the five mot ignificant bit of original pixel of the image, d i the difference between the value of three leat ignificant bit after a watermark i embedded and value of three leat ignificant bit of original pixel of the image. 5. Input the ecret key. 6. Iterate for each mall block p 0 p 1 p 2 p 3 (1) All Right Reerved 2017 IJARCET 1059

3 International Journal of Advanced Reearch in Computer Engineering & Technology (IJARCET) Volume 6, Iue 7, July 2017, ISSN: a) Compute Meage Diget 5 [10] over the mall block and then apply the XOR over the meage diget and ecret key. Fold the information to the 5 bit. If current block i mooth block the embed the firt four bit in the A poition ele embed the five bit in A poition. b) Compute the mean of the mall block and convert it into the binary form. Embed the two mot ignificant bit in M poition. c) If current block i the lat block then go to tep 7 ele go to tep 6(a). 7. Compute the performance parameter and return the watermarked image. Tamper detection procedure: The image tamper detection model revere the whole procedure of embedding and verifie the embedding to recognize the tampered part. In our cheme two level tamper detection i performed in order to detect the tampered region in the image. 1. Input the tampered image. 2. Divide the entire image into k = M N/64 non-overlapping large block of 8 8. Each large block conit of 16 mall block of 2 2. M and N are height and width of image repectively. 3. Compute gray level variance of each large block and ort it in decending order. The top (M N)/ (64 3) block are non-mooth block and the remaining are mooth block. 4. Input the ecret key ued during the embedding proce. 5. Initialize a binary image equal to the ize of input image, detect binary. 6. Iterate for each mall block a) Compute Meage Diget 5 [10]over the mall block and then apply the XOR over the meage diget and ecret key. Fold the information to the 5 bit. If current block i mooth block the compare the firt four bit with the pre-embedded information in the A poition ele compare the 5 bit with the pre-embedded information in A poition. b) Compute the mean of the mall block and convert it into the binary form. Extract the two mot ignificant bit of the mean and compare it with the pre-embedded information in M poition. c) If both the information doe not match with pre-embedded information then current 2 2 block i marked a invalid and the correponding pixel in detect binary. are aigned the value 1 (i.e. white color to repreent the tampered part). d) If current block i the lat block then go to tep 7 ele go to tep 6(a). 7. Return the detect binary image mentioning the tampered region and compute the performance parameter. IV. EXPERIMENTATION AND RESULTS All the experiment are performed in MATLAB (R2010a) on a PC with 1.70 GHz Intel Core i3 CPU, 4 GB RAM and 1 TB HDD under window 8 environment. In order to evaluate the performance of the propoed ytem copy-move attack ha been applied on the watermarked image uing the adobe Photohop. All the image are of ize and are in tiff format. The performance evaluation metric ued are Peak Signal to Noie Ratio (PSNR), Fale negative rate (FNR), Fale poitive rate (FPR), True poitive rate (TPR) and True negative rate (TNR). PSNR i meaured in decibel and i given by following equation: where MSE i mean quare error and i given by: (3) where and repreent the length and width of the two dimenional image repectively In order to meaure the tamper detection accuracy FNR, FPR, TPR and TNR are ued. Fale negative rate i the proportion of actual tampered pixel that were erroneouly reported a untampered pixel. (4) Fale poitive rate i the proportion of actual untampered pixel that were erroneouly reported a tampered pixel. True poitive rate i the proportion of actual tampered pixel that are reported a tampered pixel. (6) True negative rate i the proportion of actual untampered pixel that were reported a untampered pixel. where repreent True Poitive, repreent Fale Negative, repreent Fale Poitive and repreent True Negative. True Poitive mean the number of pixel that are tampered and judged a tampered. Fale Negative mean the number of pixel that are tampered but judged a untampered. Fale Poitive mean the number of pixel that are untampered but judged a tampered. True negative mean the number of pixel that are untampered and judged a untampered. Table I. PSNR, FPR, FNR, TPR, TNR of propoed cheme. (5) (7) (2) Image name PSNR (db) FPR FNR TNR TPR Baboon Barbara Jet plane Pirate Pepper Lena Gold Bridge Couple Zelda Elaine Sailboat Average All Right Reerved 2017 IJARCET 1060

4 International Journal of Advanced Reearch in Computer Engineering & Technology (IJARCET) Volume 6, Iue 7, July 2017, ISSN: Table II. Comparion between experimental data of propoed method and Hu and Tu cheme [9]. Method PSNR (db) FPR FNR TNR TPR Propoed Hu and Tu (a) (b) (c) (d) (e) (f) (g) (h) ( i) (j) (k) (l) Fig. 3 Watermarked image (a) Baboon (b) Barb (c) Jet plane (d) Pirate (e) Pepper (f) Lena (g) Gold (h) Bridge (i) Couple (j) Zelda (k) Elaine (l) Sailboat (a) (b) ( c) (d) (e) (f) (g) (h) All Right Reerved 2017 IJARCET 1061

5 International Journal of Advanced Reearch in Computer Engineering & Technology (IJARCET) Volume 6, Iue 7, July 2017, ISSN: (i) (j) (k) (l) Fig. 4 Copy-move attack experiment (a) Baboon (b) Barb (c) Jet plane (d) Pirate (e) Pepper (f) Lena (g) Gold (h) Bridge (i) Couple (j) Zelda (k) Elaine (l) Sailboat (a) (b) (c) (d) (e) (f) (g) (h) (i ) (j) (k) (l) Fig.5 Tamper detection reult of copy move attack (White zone are tampered zone). V. CONCLUSION In thi paper fragile watermarking cheme baed on adaptive embedding i implemented. The experimental reult of PSNR how that the watermarked image have high viual imperceptibility. Comparion reult of Table II how that our cheme outperform the exiting technique by reducing fale poitive rate and fale negative rate and increaing the PSNR of watermarked image. Future cope of thi work include extending thi cheme for authentication of color image. ACKNOWLEGDEMENT With profound gratitude and due regard, I whole heartedly and incerely acknowledge the effort, encouragement and proper guidance by Dr. Sukhjeet Kaur Ranade Aociate Profeor, Department of Computer Science, Punjabi Univerity, Patiala. REFERENCES [1] S. Walton, Information authentication for a lippery new age, Dr. Dobb Journal, 20.4(1995): [2] M.M. Yeung and F. Mintzer, An Inviible Watermarking Technique for Image Verification", International Conference on Image Proceing, IEEE (1997). [3] C. Kailaanathan,"Fragile watermark baed on polarity of pixel point." Image and Signal Proceing and Analyi, Proceeding of the 3rd International Sympoium on. 2(2003). [4] T.Y. Lee and S. D. Lin, "Dual watermark for image tamper detection and recovery." Pattern recognition (2008): [5] X. Zhang and S. Wang, "Fragile watermarking with error-free retoration capability." IEEE Tranaction on Multimedia 10.8 (2008): [6] S. Rawat and B. Raman, "A chaotic ytem baed fragile watermarking cheme for image tamper detection." AEU-International Journal of Electronic and Communication (2011): All Right Reerved 2017 IJARCET 1062

6 International Journal of Advanced Reearch in Computer Engineering & Technology (IJARCET) Volume xx, Iue xx, Month 20xx, ISSN: [7] L. Teng, X. Wang and X. Wang, "Cryptanalyi and improvement of a chaotic ytem baed fragile watermarking cheme." AEU-International Journal of Electronic and Communication 67.6 (2013): [8] D. Caragata, et al, "Cryptanalyi of an improved fragile watermarking cheme." AEU-International Journal of Electronic and Communication 70.6 (2016): [9] C.S. Hu and S.F. Tu,"Image tamper detection and recovery uing adaptive embedding rule." Meaurement 88 (2016): [10] R. Rivet, RFC1321: The MD5 meage-diget algorithm, RFC Editor,United State, Yadwinder Kaur i a tudent of M.Tech (CSE) in Department of Computer Science, Punjabi Univerity, Patiala carrying out her reearch work under the guidance of Dr. Sukhjeet Kaur Ranade. Her main reearch interet i digital watermarking. Dr. Sukhjeet Kaur Ranade i preently erving a Aociate Profeor in Department of Computer Science, Punjabi Univerity, Patiala. Her key reearch area are image proceing and information hiding. She ha publihed more than 50 paper in variou journal and conference of international and national repute. All Right Reerved 2017 IJARCET 1063