Authentication of identification documents and banknotes

1. A method comprising:

selecting a set of data from at least one of a photograph or information, wherein the information and photograph are carried by a physical document, the document further including a design;

reducing the selected set of data to a first number; and

altering characteristics of the design according to the first number,

wherein evidence of the altered design characteristics is found through analysis of data corresponding to the altered design characteristics in both a spatial domain and a frequency domain, and

wherein the evidence in either of the spatial domain or the frequency domain provides an authentication clue.

2. The method according to claim 1 , wherein the design comprises at least one of a group of concentric circles or a plurality of parallel lines.

3. The method of claim 2 wherein said altering characteristics of the design comprises adjusting spacing between adjacent circles or lines according to the first number.

4. The method of claim 3 wherein said reducing comprises hashing the selected set of data.

5. The method of claim 3 wherein said reducing comprises hashing the selected set of data to obtain a result, and offsetting a predetermined number with the result to yield the first number.

6. The method of claim 2 wherein spatial domain evidence comprises a spatial spacing distance between adjacent circles or between parallel lines.

7. The method of claim 6 wherein frequency domain evidence comprises a circle radius when the design comprises the concentric circles and a frequency point located an identifiable distance from a DC component frequency point when the design comprises the parallel lines.

8. A method to authenticate the document of claim 1 , said method comprising:

selecting the set of data from the photograph or information carried by the document;

reducing the selected set of data to the first number; and

comparing the first number with the characteristics of the design.

9. The method of claim 8 wherein the comparing comprises:

analyzing characteristics of the document design in a frequency domain;

converting the first number to an expected radius or distance;

comparing the expected radius or distance with the frequency domain characteristics; and

determining that the document is authentic when the expected radius or distance coincides with the frequency domain characteristics.

10. The method of claim 8 wherein the comparing comprises:

in a spatial domain analyzing a spacing between lines or circles of the design;

comparing the spacing with the first number; and

determining that the document is authentic when the spacing coincides with the first number.

11. The method of claim 1 further comprising embedding a digital watermark in the document, the digital watermark including a key identifying the set of data.

12. A method of marking a banknote comprising:

providing a pattern including a group of concentric shapes;

modifying characteristics of the pattern, said act of modifying resulting at least in part in a modified pattern; and

changing data representing information or artwork to be placed on or in the banknote in accordance with the modified pattern,

wherein evidence associated with the modified pattern is found through analysis of data corresponding to the modified pattern in a frequency domain, and

wherein the evidence in the frequency domain provides an indication.

13. The method of claim 12 wherein the indication indicates that the banknote is a banknote.

14. The method of claim 12 wherein the indication is utilized by a copy deterrent system.

15. The method of claim 12 wherein the data corresponding to the modified pattern is obtained from optically scanning a marked banknote.

16. The method of claim 12 wherein the pattern is provided from a plurality of different patterns.

17. The method of claim 12 wherein the artwork comprises at least one item from a group of items comprising: line art, artwork, image, graphic and design.

18. A banknote produced according to claim 12 .

19. The method of claim 12 wherein said act of providing a pattern including a group of concentric shapes includes accessing a database or library including a plurality of such patterns to select a suitable pattern.

20. An apparatus comprising:

a receiver mechanism to receive digital data representing a physical banknote, the banknote comprising a modified pattern including a group of concentric shapes, the modified pattern being represented on the banknote through changes to information or data carried by the banknote; and

a processor comprising hardware or processing circuitry to:

transform the data into a frequency domain, wherein evidence associated with the modified pattern is found through analysis of data corresponding to the modified pattern in the frequency domain,

identify the evidence in the frequency domain, the evidence indicating that the banknote is a banknote; and

provide a signal to prevent reproduction of the banknote based at least in part on the evidence.

21. The apparatus of claim 19 further comprising memory in communication with the processor, the memory comprising executable instructions to execute said transform, said identify and said provide.

22. A banknote comprising a modified pattern including a group of concentric shapes, the modified pattern being represented on the banknote through alterations to artwork or graphics carried by the banknote, wherein evidence associated with the modified pattern is found through analysis of data corresponding to the modified pattern in a frequency domain, and wherein the evidence provides an indication.

23. The banknote of claim 22 wherein the indication indicates that the banknote is a banknote.

24. The banknote of claim 22 wherein the indication is to be utilized by a copy deterrent system.

25. The banknote of claim 22 wherein the data corresponding to the modified pattern is obtained from optical scan data corresponding to the modified pattern.

26. The banknote of claim 22 wherein the modified pattern is generally imperceptible to a human observer of the banknote.