| Number | Name | Date | Kind |
|---|---|---|---|
| 4743747 | Fougere | May 1988 | A |
| 4965829 | Lemelson | Oct 1990 | A |
| 5748780 | Stolfo | May 1998 | A |
| 6049775 | Gertner | Apr 2000 | A |
| 6064995 | Sansone | May 2000 | A |
| 6119051 | Anderson | Sep 2000 | A |
| 6398106 | Ulvr et al. | Jun 2002 | B1 |
| WO 0225597 | Sep 2001 | A1 |
| Entry |
|---|
| Cullen, M; Pinstov, I. ; Romansky, B., Reading encrypted postal indicia, Institution of Electrical Engineers, IEEE Computer Society Press, 1995, Part vol. 2, p. 1018-23 vol. 2. |