Method and system for validating a security marking
View Patent ↗A method and system for authenticating an item by using a security marking. The security marking is provided on the item with an OVD ink capable of absorbing light in a visible wavelength range to appear visibly black and producing a red fluorescent emission under ultraviolet excitation. Under visible light illumination and ultraviolet excitation, a visible image and a fluorescent image are obtained from the security marking using image scanners. The images are compared to find a substantial match with each other. The security marking can be a postage indicium, a barcode, a symbol, a message or an image. The item to be authenticated can be a mailpiece, a banknote, a tag, a ticket, a document, an identification card, or the like.
1. A method for authenticating an item having a surface with a security marking printed thereon, said method comprising the steps of:
processing with scanning equipment an item with a security marking created with a single medium capable of absorbing light in a visible wavelength range to appear visibly black, the medium also producing a fluorescent emission under excitation illumination, wherein the fluorescent emission has a first wavelength and the excitation illumination has a second wavelength shorter than the first wavelength;
acquiring a first image of the security marking in the visible wavelength range under illumination of visible light;
acquiring a second image of the security marking from the fluorescent emission under excitation illumination; and
verifying authenticity of the item using the first image and the second image.
2. The method of claim 1 , wherein the step of verifying the authenticity comprises determining that the first and second images are physically coincident.
3. The method of claim 1 , wherein the step of verifying the authenticity comprises comparing the first image to the second image for determining a substantial match between the first image and the second image.
4. The method of claim 3 , wherein said comparing step is carried out visually.
5. The method of claim 3 , wherein said comparing step comprises the steps of:
obtaining a value representative of a correlation between the first image and the second image; and
comparing the value to a predetermined threshold.
6. The method of claim 1 , wherein the medium comprises an ink.
7. The method of claim 1 , wherein the medium comprises an ink which can be used in an inkjet printer for providing said security marking.
8. The method of claim 1 , wherein the excitation illumination is ultraviolet excitation.
9. The method of claim 1 , wherein the fluorescent emission is a red fluorescent emission.
10. The method of claim 1 , wherein the item comprises a mailpiece and the security marking comprises a postage indicium.
11. The method of claim 1 , wherein the item is a banknote.
12. The method of claim 1 , wherein the item is a document.
13. A system for authenticating an item having a surface with a security marking printed thereon, said system comprising:
scanning equipment for processing the item with a security marking created using a single medium capable of absorbing light in the visible wavelength range under illumination of visible light, the medium producing a fluorescent emission under excitation illumination, wherein the fluorescent emission has a first wavelength and the excitation illumination has a second wavelength shorter than the first wavelength,
a first means, responsive to the visible light, for acquiring a first image of the security marking for providing a first signal indicative of the first image;
a second means, responsive to the fluorescent emission, for acquiring a second image for providing a second signal indicative of the second image; and
a third means, responsive to the first signal and the second signal, for verifying authenticity of the item using the first image and the second image.
14. The system of claim 13 , wherein the third means determines that the first and second images are physically coincident.
15. The system of claim 13 , wherein the third means compares the first image to the second image for determining a substantial match between the first image and the second image.
16. The system of claim 13 , wherein the third means comprises a correlating means for obtaining a value indicative of the match between the first image and the second image, and said value is used to determine the match based on a predetermined threshold.
17. The system of claim 13 , wherein the first means comprises an image scanner.
18. The system of claim 13 , wherein the first means comprises a digital camera.
19. The system of claim 13 , wherein the first means comprises a video camera.
20. The system of claim 13 , wherein the second means comprises an image scanner.
21. The system of claim 13 , wherein the second means comprises a digital camera.
22. The system of claim 13 , wherein the second means comprises a video camera.
23. The system of claim 13 , further comprising a printer for printing the security marking.
24. The system of claim 13 , further comprising an inkjet printer for printing the security marking.
25. The system of claim 13 , further comprising a visible light source for illuminating the security marking.
26. The system of claim 13 , further comprising an ultraviolet light source for providing ultraviolet excitation to the security marking.
27. The system of claim 26 , wherein the fluorescent emission is in a first wavelength range and the ultraviolet light source provides light in a second wavelength range which is shorter than the first wavelength range.
28. The system of claim 27 wherein the first wavelength range is between 400 and 1100 nanometers.