Capturing Physical Feature Data

• US 20070187505A1
• Filed: 01/19/2007
• Published: 08/16/2007
• Est. Priority Date: 01/23/2006
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey, Rodriguez, Tony
• Granted Patent: US 8,077,905 B2
• Time in Patent Office: Days
• US Class Current: 235/454
• CPC Class Codes: G06F 16/211 Schema design and management
• CPC Class Codes: G06F 40/106 Display of layout of documents; Previewing
• CPC Class Codes: G06K 19/14 the marking being sensed by radiation
• CPC Class Codes: G06Q 20/347 Passive cards
• CPC Class Codes: G06Q 20/388 using mutual authentication without cards, e.g. challenge-response
• CPC Class Codes: G06V 10/60 relating to illumination properties, e.g. using a reflectance or lighting model
• CPC Class Codes: G06V 20/80 Recognising image objects characterised by unique random patterns
• CPC Class Codes: G07D 7/004 using digital security elements, e.g. information coded on a magnetic thread or strip
• CPC Class Codes: G07D 7/12 Visible light, infrared or ultraviolet radiation
• CPC Class Codes: G07D 7/121 Apparatus characterised by sensor details
• CPC Class Codes: G07D 7/2033 Matching unique patterns, i.e. patterns that are unique to each individual paper
• CPC Class Codes: G07F 7/08 by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/0813 Specific details related to card security
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G07F 7/1016 Devices or methods for securing the PIN and other transaction-data, e.g. by encryption arrangements for secret communication, see H04L9/00
• CPC Class Codes: G07F 7/125 Offline card verification
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/3278 using physically unclonable functions [PUF]

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.

Claims

1. A method comprising:

assessing directional albedo data relating to a surface of a first article; and

storing data corresponding to said assessment for verification of said article.

2. The method of claim 1 in which said assessing comprises, for each of plural regions on a surface of said article, determining a wobble angle at which reflectance from said article is at a maximum.

3. The method of claim 1 in which said assessing comprises capturing light reflected from a region of a card towards a first direction, and towards a second direction, and determining therefrom a wobble angle at which reflectance from said region is at a maximum.

4. The method of claim 1 that further comprises illuminating the article with diffuse illumination.

5. The method of claim 1, that includes assessing directional albedo data relating to a surface of an identification document.

6. A method of issuing driver licenses that includes fabricating a license, and providing same to an applicant, further characterized by, prior to said providing, collecting a unique set of physical measurement data from each license, and storing same in a database, wherein the stored data can later be consulted to identify said license.

7. The method of claim 6 wherein said collecting comprises capturing information related to topographic minutiae from each license.

8. The method of claim 6 wherein said collecting comprises capturing light reflected from a region of a license towards a first direction, and towards a second direction, and determining therefrom a wobble angle at which reflectance from said region is at a maximum.

9. The method of claim 6, further characterized by processing the license prior to said providing, so as to deliberately impart thereto a random physical feature, and collecting a set of measurement data related thereto.

10. A method comprising:

receiving a card, the card having a set of plural physical features that, in the aggregate, define an initial state;

applying a stimulus to the card, said stimulus causing plural of said physical features to change, thereby defining a second state of said set of features; and

storing data related to said second state.

11. The method of claim 10 that further includes using said second state of said set of features in connection with a cryptographic function.

12. The method of claim 10 wherein the card comprises plural regions, and said set of features comprises a parameter associated with each of said regions.

13. The method of claim 10 wherein said parameters comprise directional albedo parameters.

14. The method of claim 10 wherein said stimulus comprises a physical pressure force, which changes a surface topology of said card.

15. The method of claim 10 wherein said stimulus comprises localized application of electromagnetic energy to certain areas of said card.

16. The method of claim 15 wherein said stimulus comprises laser irradiation, applied to said card from a first direction, and further irradiation, applied to said card from a second, different, direction.

17. The method of claim 15 wherein said stimulus comprises laser irradiation, applied to first positions on said card for a first interval of time, and applied to second positions on said card for a second, longer interval of time.

18. The method of claim 10 wherein said stimulus comprises a liquid sprayed on said card.

19. The method of claim 10 wherein said applying has a random aspect.

20. (canceled)