Sensing data from physical objects

• US 8,224,018 B2
• Filed: 04/24/2007
• Issued: 07/17/2012
• Est. Priority Date: 01/23/2006
• Status: Expired due to Fees

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Rodriguez, Tony F.
• Primary Examiner(s): Akhavannik, Hadi
• Application Number:
  US11/739,387
• Publication Number:
  US 20080112596A1
• Time in Patent Office: 1,911 Days
• Field of Search: 382/100
• US Class Current: 382/100
• 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: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 2201/0062 Embedding of the watermark in text images, e.g. watermarking text documents using letter skew, letter distance or row distance
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• 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: G06V 30/413 Classification of content, e.g. text, photographs or tables
• CPC Class Codes: G07D 7/12 Visible light, infrared or ultraviolet radiation
• 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 2209/608 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 the acts:

sending challenge data from a first device to a second device;

at the second device, obtaining response data by reference to said challenge data and a physical object, wherein said obtaining includes capturing reflected non-coherent illumination from the object with a 2D photosensor to produce image data, and processing said image data; and

checking said response data against expected data to produce result data;

wherein said result data is not dependent on a particular placement of an illumination source relative to both the 2D photosensor and the physical object.

2. The method of claim 1 in which said capturing comprises capturing with a 2D optical sensor in a portable phone.

3. The method of claim 1 that includes maintaining a list of used challenge data, and checking candidate challenge data against said list.

4. The method of claim 1 in which said obtaining includes processing the image data in accordance with the challenge data to yield the response data.

5. The method of claim 1 in which the physical object is a planar card.

9. The method of claim 1 wherein said result data is not dependent on a particular placement of an illumination source relative to the 2D photosensor.

10. The method of claim 1 wherein said result data is not dependent on a particular placement of an illumination source relative to the physical object.

13. The method of claim 1 in which said checking comprises checking at the first device.

6. A method comprising the acts:

sending challenge data from a first device to a second device;

at the second device, obtaining response data by reference to said challenge data and a physical object, said obtaining including capturing image data from the object with a 2D photosensor; and

checking said response data against expected data to produce result data;

wherein said result data is not dependent on a particular placement of an illumination source relative to both the 2D photosensor and the physical object, and the method further includes determining the relative orientation between said object and said 2D photosensor by reference to said captured image data.

7. The method of claim 6 in which said determining includes decoding a steganographically encoded signal from said captured image data.

8. The method of claim 6 in which said capturing comprises capturing with a 2D optical sensor in a portable phone.

11. The method of claim 6 wherein said result data is not dependent on a particular placement of an illumination source relative to the 2D photosensor.

12. The method of claim 6 wherein said result data is not dependent on a particular placement of an illumination source relative to the physical object.

14. The method of claim 6 in which said checking comprises checking at the first device.

15. A method comprising:

producing response data responsive to a physical object and challenge data, said producing including capturing imagery from the physical object using a 2D photosensor, and processing said imagery; and

sending said response data to a checking system that can check the response data against expected data;

wherein said response data is not essentially dependent on a particular placement of an illumination source relative to both the 2D photosensor and the physical object.

16. The method of claim 15 wherein the physical object is illuminated with a non-coherent light source when capturing said imagery.

17. The method of claim 15 wherein said capturing comprises capturing with a 2D photosensor in a portable phone.

18. The method of claim 15 that includes checking the response data against said expected data to yield result data.