Data processing method and apparatus
First Claim
1. A data processing apparatus comprising:
- check bit generation means for generating a plurality of keys on the basis of pseudo random number values corresponding to pixel positions of pixels, correlating the keys with pixel positions of digital image data by a predetermined method, encrypting pixel data at the pixel positions corresponding to the keys, and generating first check bits corresponding to the pixel positions of pixels of the digital image data; and
multiplexing means for multiplexing the first check bits in corresponding pixel data of the digital image data,wherein the predetermined method that correlates the keys with pixel positions determines correspondence between a plurality of neighboring pixel data and one key.
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Abstract
An encrypted image C(i, j) is generated by exclusively ORing pseudo random number values, which are generated using a key k0 as a key, and respective bits, except for the LSBs, of B pixel data at respective pixel positions (i, j) of digital image data I(i, j). First check bits B(i, j) corresponding to the pixel positions of pixels are generated based on the image C(i, j) and a conversion table. A digitally watermarked image I′(i, j) is obtained by embedding the first check bits in the LSBs of the corresponding pixel data of the digital image data. Check bits U(i, j) are obtained by encrypting pixel data by exclusively ORing respective bits, except for the LSBs, of B pixel data at positions (i, j) of the image I′(i, j) and the pseudo random numbers. If each check bit U(i, j) matches the LSB of the corresponding B pixel data, it is determined that the corresponding pixel is free from tampering.
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Citations
6 Claims
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1. A data processing apparatus comprising:
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check bit generation means for generating a plurality of keys on the basis of pseudo random number values corresponding to pixel positions of pixels, correlating the keys with pixel positions of digital image data by a predetermined method, encrypting pixel data at the pixel positions corresponding to the keys, and generating first check bits corresponding to the pixel positions of pixels of the digital image data; and multiplexing means for multiplexing the first check bits in corresponding pixel data of the digital image data, wherein the predetermined method that correlates the keys with pixel positions determines correspondence between a plurality of neighboring pixel data and one key.
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2. A data processing apparatus comprising:
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check bit generation means for generating a plurality of keys on the basis of pseudo random number values corresponding to pixel positions of pixels, correlating the keys with pixel positions of digital image data by a predetermined method, encrypting pixel data at the pixel positions corresponding to the keys, and generating first check bits corresponding to the pixel positions of pixels of the digital image data; and multiplexing means for multiplexing the first check bits in corresponding pixel data of the digital image data, wherein the predetermined method that correlates the keys with pixel positions determines correspondence between a plurality of randomly selected pixel data and one key.
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3. A data processing apparatus comprising:
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check bit generation means for generating a plurality of keys on the basis of pseudo random number values corresponding to pixel positions of pixels, correlating the keys with pixel positions of digital image data by a predetermined method, encrypting pixel data at the pixel positions corresponding to the keys, and generating first check bits corresponding to the pixel positions of pixels of the digital image data; and multiplexing means for multiplexing the first check bits in corresponding pixel data of the digital image data, wherein the predetermined method that correlates the keys with pixel positions determines correspondence between one randomly selected pixel data and one key.
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4. A data processing method comprising:
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a check bit generation step of generating a plurality of keys on the basis of pseudo random number values corresponding to pixel positions of pixels, correlating the keys with pixel positions of digital image data by a predetermined method, encrypting pixel data at the pixel positions corresponding to the keys, and generating first check bits corresponding to the pixel positions of pixels of the digital image data; and a multiplexing step of multiplexing the first check bits in corresponding pixel data of the digital image data, wherein the predetermined method that correlates the keys with pixel positions determines correspondence between a plurality of neighboring pixel data and one key.
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5. A data processing method comprising:
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a check bit generation step of generating a plurality of keys on the basis of pseudo random number values corresponding to pixel positions of pixels, correlating the keys with pixel positions of digital image data by a predetermined method, encrypting pixel data at the pixel positions corresponding to the keys, and generating first check bits corresponding to the pixel positions of pixels of the digital image data; and a multiplexing step of multiplexing the first check bits in corresponding pixel data of the digital image data, wherein the predetermined method that correlates the keys with pixel positions determines correspondence between a plurality of randomly selected pixel data and one key.
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6. A data processing method comprising:
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a check bit generation step of generating a plurality of keys on the basis of pseudo random number values corresponding to pixel positions of pixels, correlating the keys with pixel positions of digital image data by a predetermined method, encrypting pixel data at the pixel positions corresponding to the keys, and generating first check bits corresponding to the pixel positions of pixels of the digital image data; and a multiplexing step of multiplexing the first check bits in corresponding pixel data of the digital image data, wherein the predetermined method that correlates the keys with pixel positions determines correspondence between one randomly selected pixel data and one key.
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Specification