Methods and Cards Employing Optical Phenomena
First Claim
Patent Images
1. A method that includes assessing directional albedo data relating to a first article, and determining—
- by reference to said data and earlier-assessed albedo data, determining an identity of said article.
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Accused Products
Abstract
Directional albedo of a particular article, such as an identity card, is measured and stored. When the article is later presented, it can be confirmed to be the same particular article by re-measuring the albedo function, and checking for correspondence against the earlier-stored data. The re-measuring can be performed through us of a handheld optical device, such as a camera-equipped cell phone. The albedo function can serve as random key data in a variety of cryptographic applications. The function can be changed during the life of the article. A variety of other features are also detailed.
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Citations
17 Claims
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1. A method that includes assessing directional albedo data relating to a first article, and determining—
- by reference to said data and earlier-assessed albedo data, determining an identity of said article.
- View Dependent Claims (2, 3, 4, 5, 6)
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7. A method comprising:
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sensing an attribute from an object, from first and second different directions;
producing data therefrom; and
by reference to said produced data, in conjunction with earlier-stored data, making a determination concerning said object. - View Dependent Claims (8, 9, 10)
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- 11. A card construction for use with ID documents, the card comprising a substrate and at least one layer thereon, characterized in that a layer thereof includes a material responsive to stimulus to change an optical property thereof.
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14. (canceled)
Specification