Detectability Improved Tamper Detection Scheme for Absolute Moment Block Truncation Coding Compressed Images Source: Symmetry, Vol. 10, No. 8, pp. 318 (1-17), Aug. 2018 Author: Wien Hong, Xiaoyu Zhou, Der-Chyuan Lou, Xiaoqin Huang and Cancan Peng Speaker: Su Guodong Date: 2019/05/16

Outline Introduction Related work Proposed scheme Experiments Conclusions

Introduction(1/2) Images 46.5 KB Compressed Original 3010 KB

Introduction(2/2) Tamper Authentication (Tamper detection)

Related work---AMBTC AMBTC compression code: ( h, l , bm ) 130 92 133 137 143 124 106 116 Low quantization level l: 122 bm 130 92 161 165 133 171 169 170 137 175 150 143 124 194 106 116 122 169 1 161 165 171 169 170 175 150 194 High quantization level h: 169 5

Proposed scheme(1/8) ---Generation of Authentication codes (ACs) AMBTC AC: ( a + b ) bits ( h, l , bm ) h 8-a a (hM )d ( a + b ) bits AC Hash function bm aca acb (lM )d 8-b b l

Proposed scheme(2/8)---Embedding of ACs AMBTC AC: ( a + b ) bits ( h, l , bm ) ( h’, l’, bm ) h 8-a a 8-a a (hM )d*2a +(aca )d (hM )d ( a + b ) bits AC (aca )d Hash function bm aca acb (acb )d (lM )d (lM )d*2b +(acb )d 8-b b 8-b b l

Proposed scheme(3/8)---Embedding of ACs AMBTC AC: ( 4 + 3 ) bits ( 169, 122 , ‘0011011101100100’ ) ( 166, 126 , ‘0011011101100100’ ) h 1010 1001 1010 0110 (hM )d*24 +(ac4 )d (hM )d =10 bm= ‘0011011101100100’ (ac4 )d = (0100)10=6 ( 0110 110) Hash function aca acb (ac3 )d = (110)10 = 6 (lM )d =15 (lM )d*23 +(ac3 )d 01111 010 01111 110 l

Proposed scheme(4/8)---Results of LSBR

Proposed scheme(5/8)---The MSBs Perturbation Technique (MSBP) AC: ( a + b ) bits Minimize: (h-h’) 2+(l-l’)2 ( h, l , bm ) ( h’, l’, bm ) h Nine combinations 8-a a 8-a a |(hM )d -(h’M )d |<=1 (h’M )d*2a +(ac’a )d (hM )d (h’M )d (ac’a )d Hash function bm aca acb (ac’b )d (l’M )d (lM )d (l’M )d*2b +(ac’b )d |(lM )d -(l’M )d |<=1 8-b b 8-b b l

Proposed scheme(6/8)---Results of MSBP

Proposed scheme(7/8)-The Authentication procedures First stage: ( h, l , bm ) h 8-a a (hM )d Untampered Yes ? Hash function = bm aca acb a b No (lM )d Tampered 8-b b l

Proposed scheme(8/8)-The Authentication procedures Second stage:

Experiments(1/5)

Experiments(2/5) Results of the first and second stage detections. (a) 1st stage, |ac| = 2; (b) 1st stage, |ac| = 4; (c) 1st stage incorrect detection (|ac| = 4); (d) 2nd stage, |ac| = 2; (e) 2nd stage, |ac| = 4; (f) 2nd stage incorrect detection (|ac| = 4).

Experiments(3/5)

Experiments(4/5) Second stage detection results of each method. Lin et al.’s method; (b) Li et al.’s method; (c) Zhong et al.’s method; (d) Proposed method.

Experiments(5/5)

Conclusions Proposed the MSBs Perturbation Technique to optimize the AMBTC compressed image quality Provided the 8-bit authentication code for high tampering detection rate Adjustable the authentication codes' generation

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