Equipment employing watermark-based authentication function
First Claim
1. Electronic equipment including an authentication function, the equipment including a steganographic watermark detector that checks sampled data for the presence of first and second steganographic watermarks, the first watermark being relatively frail and the second watermark being relatively robust, the equipment determining that the sampled data is authentic only if both watermarks are present.
6 Assignments
0 Petitions
Accused Products
Abstract
Image, video, or audio data is encoded with both a frail and a robust watermark. The two watermarks respond differently to different forms of processing (e.g., copying the object may render the frail watermark unreadable), permitting an original object to be distinguished from a processed object. Appropriate action can then taken in response thereto.
515 Citations
8 Claims
- 1. Electronic equipment including an authentication function, the equipment including a steganographic watermark detector that checks sampled data for the presence of first and second steganographic watermarks, the first watermark being relatively frail and the second watermark being relatively robust, the equipment determining that the sampled data is authentic only if both watermarks are present.
- 6. Electronic equipment including an authentication function, the authentication function includes a steganographic watermark detector that checks sampled data for the presence of first and second steganographic watermarks, wherein the sampled data corresponds to a printed document, and wherein an original printed document includes first and steganographic watermarks cooperating in an expected manner to evidence authenticity of the original printed document, said electronic equipment determines that the printed document is an original printed document only if both watermarks are present and if the watermarks evidence the expected cooperation.
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8. A method to differentiate copies of an original document from the original document, wherein the original document includes a first digital watermark and a second digital watermark, said method comprising:
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obtaining a first metric based on a comparison of the first and second digital watermarks in the original document;
reading the first and second watermarks from a copy of the original document and comparing the watermarks to obtain a second metric; and
using differences between said first and second metrics to differentiate an original document from a copy of the original document.
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Specification