1. A Data-Hiding Technique With Authentication, Integration, and Confidentiality for Electronic Patient Records
Chao, Hui-Mei, Hsu, Chin-Ming, and Miaou, Shaou-Gang, IEEE Transactions on Information Technology in Bimedicine, VOL. 6, NO. 1, MARCH 2002, pp
Adviser : Dr. Chang, Chin-Chen
Reporter : Chi, Kang-Liang
Date : 2003/04/08
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2. Outline Introduction Bipolar TER Multiple-Base Algorithm
( TER : Tolerant Error Range )
Data-Hiding Methods
Experimental Results
Conclusions
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3. Introduction
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4. Bipolar TER Multiple-Base Algorithm
Multiple-base sequences are –3, 7, 8, -4, 5, …
The number 500
Since |(-3)*7*8| < |(-3)*7*8*(-4)|, then the four
numbers –3, 7, 8, -4 would be used as the bases for 500 , and the number “4” is stored in the key chain .
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5. Bipolar TER Multiple-Base Algorithm
500 = 4*125+0
125 = 8*15+5
15 = 7*2+1
2 = 3*0+2
(2)*7*8*4+(1)*8*4+(5)*4+(0)=500
The temporary converted values would be 2150.
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6. Bipolar TER Multiple-Base Algorithm
(-3, 7, 8, -4)+(2, 1, 5, 0)*sign(-3, 7, 8, -4)
= (-1, 6, 3, -4)
A new bipolar TER base (-1, 6, 3, -4) is obtained .
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7. Data-Hiding Methods
(1) Hiding a Digital Signature :
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8. Data-Hiding Methods
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9. Data-Hiding Methods
(2) Hiding a Diagnostic Report or a Segment of ECG signal .
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10. Data-Hiding Methods Hiding a Diagnostic Report : Ex : 216 = 13*16+8
|13| < |13*10|
13 = 10*1+3
1 = 13*0+1
(1)*10+(3)=13
(13, 10)+(1, 3)*sign(13, 10) = (14, 13)
Using (14, 13) to modify the bipolar TER base .
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11. Data-Hiding Methods Hiding a Segment of ECG Signal :
Data of the most frequently appeared are assigned to be zeros as a base-line value .
Using Bipolar TER Multiple-Base Algorithm to modify the bipolar TER base .
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12. Experimental Results Table I
Performance of hidden and JPEG decompressed images in terms of PSNR in decibels
Table II
Performance of hidden and JPEG decompressed images terms of the variance of TER
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13. Experimental Results Table III
Comparison of the conventional encryption/decryption method and the proposed method
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14. Conclusions
Different sizes of key and mark images are generated when different data are encrypted .
Less processing time is needed .
The confidentiality can be achieved by decrypting the entire message not only with digital signatures, but also with the exact copy of the original mark image and hidden image .
The authentication can be provided with several objects .
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