发明名称 |
Methods, systems, and subcombinations useful with physical articles |
摘要 |
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. |
申请公布号 |
EP2293222(A1) |
申请公布日期 |
2011.03.09 |
申请号 |
EP20100181412 |
申请日期 |
2007.01.19 |
申请人 |
DIGIMARC CORPORATION |
发明人 |
RHOADS, GEOFFREY B.;RODRIGUEZ, TONY, F.;BRADLEY, BRETT, A. |
分类号 |
G06K9/00 |
主分类号 |
G06K9/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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