Covert authentication method and apparatus

• US 20050239207A1
• Filed: 04/22/2004
• Published: 10/27/2005
• Est. Priority Date: 04/22/2004
• Status: Active Grant

• Current Assignee: Authentix, Inc.
• Original Assignee: Kodak Graphic Communications Canada Company (Eastman Kodak Company)
• Inventors: Gelbart, Daniel
• Granted Patent: US 7,687,271 B2
• Time in Patent Office: Days
• US Class Current: 436/56
• CPC Class Codes: G06K 19/086 with markings consisting of randomly placed or oriented elements, the randomness of the elements being useable for generating a unique identifying signature of the record carrier, e.g. randomly placed magnetic fibers or magnetic particles in the body of a credit card
• CPC Class Codes: G06V 20/80 Recognising image objects characterised by unique random patterns
• 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: G07D 7/2075 Setting acceptance levels or parameters
• CPC Class Codes: Y10T 436/13 Tracers or tags

Abstract

An authentication system uses the unique distribution of an invisible taggant as a “signature” to identify an item. The verification is error tolerant. The taggant is made visible to a camera by special illumination. Inert taggants, with no optical activity, can be made visible by their thermal properties.

Claims

1. An authentication method comprising the steps of:

a. tagging an item by randomly distributing a taggant in at least part of the item, the taggant being invisible to an unaided human eye under normal conditions;

b. optically detecting said taggant by

i. placing a detector in proximity to the item and

ii. generating data related to the taggant distribution; and

c. verifying whether the data matches previous data from previously detected items.

2. A method as in claim 1 wherein the item is printed with a liquid, the liquid comprising printing ink and taggant.

3. A method as in claim 1 wherein the item includes a registration feature detectable by the detector.

4. A method as in claim 1 wherein the verifying step is invariant to the exact placement of the detector relative to the item.

5. A method as in claim 1 wherein the verifying step is tolerant to errors.

6. A method as in claim 1 wherein the verifying step comprises storing at least part of the previous data from previously detected items in RAM.

7. An authentication system for authenticating an item, the authentication system comprising:

a. a taggant mixed with a material, at least a part of the item comprising the material;

b. a detector capable of detecting location of the taggant without being required to contact the taggant;

c. a database for storing taggant locations from one or more items; and

d. a verification unit for checking whether the item matches any of the one or more items in the database.

8. An authentication method comprising the steps of:

a. tagging an item by randomly distributing a taggant in at least part of the item;

b. detecting the taggant by

i. placing a detector in proximity to the item and

ii. generating first data related to the taggant distribution;

c. marking the item with a code related to the first data; and

d. verifiying the item at a future time by

i. placing a detector in proximity to the item,

ii. generating second data related to the taggant distribution and

iii. comparing the second data to the marked code.

9. A detector for detecting invisible taggant in an item, the detector comprising of:

a. an electronic camera capable of forming an image of a taggant distribution in the item;

b. means of making the taggant detectable to the camera; and

c. image processing means capable of

i. detecting a registration mark on the item and

ii. registering the taggant distribution to the registration mark.