Data hiding based Hamming code Speaker Su Guodong

Data hiding based Hamming code Speaker: Su Guodong Date: 2019 -01 -31

Outline • Matrix coding [1] • Nearest covering code [2] • Hamming+1 [3] • Hamming+3 [4] • Comparisons [1] Westfeld A. , “F 5—a steganographic algorithm, ” International workshop on information hiding. Springer, Berlin, Heidelberg, 2001: 289 -302. [2] Chang C. C. , Chou Y. C. , “Using nearest covering codes to embed secret information in grayscale images, ” Proceedings of the 2 nd international conference on Ubiquitous information management and communication. ACM, 2008: 315 -320. [3]Zhang W. , Wang S. , Zhang X. , “Improving embedding efficiency of covering codes for applications in steganography, ” IEEE Communications Letters, 2007, 11(8). [4] Kim C. , Yang C. N. , “Improving data hiding capacity based on hamming code, ” Frontier and Innovation in Future Computing and Communications. 2 Springer, Dordrecht, 2014: 697 -706.

Matrix coding-Embedding Modified Code. Word : 1000111 Code. Word (CW): 1010111 Secret message bits: S =1 0 1 z ei 001 010 011 100 101 110 111 1000000 0100000 0010000 0001000 0000100 0000010 0000001 3

Matrix coding-Extraction Received Codeword (RCW): 1000111 Secret message bits: S =1 0 1 4

Matrix coding-Extraction The 7 -bit codeword can carry 3 secret bits by changing at most 1 bit Embedding Rate: Embedding efficiency: 5

Nearest Covering Code First, a reference data prepared for secret data embedding is constructed by classifying all possible combinations of seven bits into eight classes C 0, C 1, . . . , C 7. Classification rule: 6

Nearest Covering Code Example: C 7 C 3 7

Nearest Covering Code Example: C 3 : 8

Nearest Covering Code Secret message bits: S =0 1 1 LSB Example: Decimal digit Secret message bits: S’ =3 Size: 1 7 pixels C 3 : S’ =3 9

Nearest Covering Code Example: LSB Secret message bits: S =0 1 1 Secret message bits: S’ =3 10

Nearest Covering Code The 7 -bit Codeword can carry 3 secret bits by changing at most 1 bit 11

Hamming+1 It embeds k+1 bits into 2 k pixel using at most change one bit. (1, 8, 3): 8 pixels can carry 4 bits message by changing one bit at most. LSB Secret message bits: 12

Hamming+1 ----Example for embedding Secret message bits: LSB 0 change to 1 1 13

Hamming+1 ----Example for embedding Secret message bits: LSB 14

Hamming+1 ----Example for embedding Secret message bits: 15

Hamming+1 ----Example for extraction LSB Secret message bits: 16

Hamming+1 The 8 -bit Codeword can carry (3+1) secret bits by changing at most 1 bit 17

Hamming+3 ----Embedding It embeds k+3 bits into 2 k -1 pixels using at most change 2 bits. (1, 7, 3): 7 pixels can carry 6 bits message by changing 2 bits at most. LSB Secret message bits: 18

Hamming+3 --Embedding LSB Secret message bits: 2 LSB 19

Hamming+3 ----Extraction LSB 2 LSB Secret message bits: 20

Hamming+3 The 7 -bit codeword can carry (3+3) secret bits by changing at most 1 bit 21

Comparisons 22

Comparisons 23

Thanks! 24

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