Structure and method for secure image transmission

• US 5,541,993 A
• Filed: 05/10/1994
• Issued: 07/30/1996
• Est. Priority Date: 05/10/1994
• Status: Expired due to Fees

• Current Assignee: Eric Fan, Fan, Carey B.
• Original Assignee: Eric Fan, Fan, Carey B.
• Inventors: Fan, Carey B., Fan, Eric
• Primary Examiner(s): Cain, David C.
• Application Number:
  US08/240,347
• Time in Patent Office: 812 Days
• Field of Search: 380/18, 380/54, 380/21
• US Class Current: 380/243
• CPC Class Codes: H04N 1/4406 Restricting access, e.g. according to user identity mechanisms actuated y cards, PIN or the like in apparatus for dispensing G07F7/08
• CPC Class Codes: H04N 1/4426 involving separate means, e.g. a server, a magnetic card
• CPC Class Codes: H04N 1/4486 using digital data encryption

Abstract

A scrambled document or image generating method first divides a page of digitized electronic document into multiple segments arranged in a first order. The digitized electronic document is scrambled in a pseudo-random manner using a scrambling algorithm to produce a scrambled document in digitized electronic form, which can be used to print out a hard copy or visually examined on a display. In one embodiment, the scrambling algorithm receives as input one or more keys, which can be entered through a keyboard, or read from a storage medium. Descrambling of a scrambled digitized electronic document is accomplished by the original positions of the scrambled segments. The scrambled document in its digitized electronic form, or in its physically viewable form retain all information of the original image, and can therefore each be used as a source of the scrambled image.

Claims

1. A method for scrambling an image, comprising the steps of:

receiving a scrambling key;

storing said image in a first storage device as image data in accordance with a first data structure;

dividing said image data into a plurality of data segments, each data segment being image data corresponding to one of a plurality of designated areas in said image under a first mapping between said data segments and said designated areas;

scrambling said plurality of data segments in a pseudo-random manner using a scrambling algorithm which receives as input said scrambling key and providing as output a scrambled image formed by associating said data segments and said designated areas under a second mapping, different from said first mapping, between said data segments and said designated areas; and

storing said scrambled image in said first storage device as image data in accordance with a second data structure.

2. A method as in claim 1, further comprising the step of providing alignment markers to said scrambled image.

3. A method as in claim 1, further comprising the step of providing a second scrambling key, said scrambling algorithm receives as input both said first scrambling key and said second scrambling key.

4. A method as in claim 1, further comprising the step of transforming said scrambled image in said second data structure to a format suitable for data transmission.

5. A method as in claim 1, further comprising the step of providing as output a display of said scrambled image.

6. A method as in claim 1, further comprising the step of descrambling in a pseudo-random manner said plurality of data segments stored in accordance with said second data structure, using a descrambling algorithm which receives as input said scrambling key and providing as output a descrambled image formed by associating said data segments and said designated areas under said first mapping between said data segments and said designated area.

7. A method as in claim 1, wherein each of said first and second mappings between said data segments and said designated areas is one-to-one.

19. A method as in claim 1, wherein said method is used in a facsimile machine.

21. A method as in claim 6, further comprising, prior to said step of descrambling, the steps of:

providing said scrambled image in hard copy form; and

scanning said scrambled image in hard copy form and providing in a second storage device, said second storage device need not be the same as said first storage device, said scanned scrambled image as image data in accordance with said second data structure.

22. A method as in claim 1, wherein said method is implemented in an application-specific integration circuit.

24. A method as in claim 1, wherein said method is implemented as a program in a computer.

8. In an image scrambling or encryption application, a method for providing one or more keys to be used in a scrambling or encryption algorithm, comprising the steps of:

determining whether a first key used for data scrambling is to be received and, if said first key is to be received, receiving said first key, said first key deriving from a sequence of symbols representing keys activated from a keyboard;

determining whether a second key for data scrambling is to be received and, if said second key is to be received, receiving from a non-volatile storage medium a second key; and

applying said algorithm to an image using (i) if only said first key is received, said first key;

(ii) if only said second key is received, said second key; and

(iii) if both said first and second keys are received, using both said first and said second keys.

9. A method as in claim 8, wherein said second key comprises a key table.

10. A method as in claim 8, wherein said second key comprises data encoding a data scrambling or encryption algorithm.

11. A method as in claim 8, wherein said step of applying said algorithm includes the step of generating a secondary key from (i) said first key, if only said first key is received, (ii) said second key, if only said second key is received;

and (iii) both said first and second keys, if both said first and second keys are received.

12. A method as in claim 11, wherein said step of generating secondary keys, if both said first and second keys are received, create a secondary key by combining said first and second keys with a predetermined third key.

13. A method as in claim 9, wherein said step of applying said algorithm includes the steps of:

representing said image as a data structure in an electronic memory device, said data structure partitioning said images into a plurality of lines arranged in accordance with a first sequence; and

rearranging said plurality of lines in said data structure in accordance with a second sequence, said second sequence being derived from said secondary key.

14. A method as in claim 9, wherein said step of applying said algorithm includes the steps of:

representing said image as a data structure in an electronic memory device, said data structure partitioning said images into a one or more lines, and within each line, into a plurality of segments, said segments in each line being arranged in accordance with a first sequence; and

rearranging said segments in one of said lines in said data structure in accordance with a second sequence, said second sequence being derived from said secondary key.

15. A method as in claim 13, further comprising the step of descrambling, said step of descrambling rearranges said plurality of lines in said data structure from said second sequence to said first sequence.

16. A method as in claim 14, further comprising the step of descrambling, said step of descrambling rearranges said segments in said line in said data structure from said second sequence to said first sequence.

17. A method as in claim 14, wherein each of said segments in said data structure is associated with colors in said image, said method further comprising the steps of:

creating a segment mask, said segment mask specifying a mapping of colors; and

applying said segment mask to each of said segments to change said colors of said segments in accordance with said mapping of colors, prior to said step of rearranging.

18. A method as in claim 17, where in said colors of said image are represented by binary digits, and wherein said step of applying said segment mask comprises applying an exclusive-or function to said binary digits.

20. A method as in claim 8, wherein said method is used in a facsimile machine.

23. A method as in claim 8, wherein said method is implemented in an application-specific integration circuit.

25. A method as in claim 8, wherein said method is implemented as a program in a computer.

26. A sheet of paper on which is printed a marker indicating an area on said sheet of paper, said area designating that any image outside said area on said sheet of paper is to remain as clear text in a facsimile transmission.

27. A marker comprising a machine-readable design to be affixed to a designated area of a sheet of paper for specifying that any image printed on said sheet of paper is to be transmitted in a facsimile transmission as clear text.

28. A marker as in claim 27, wherein said marker is printed on paper coated on one side with an adhesive material, such that said marker is to be affixed to said sheet of paper by said adhesive material.

29. A marker as in claim 28, wherein said marker is generated by a wordprocessor on said sheet of paper.

30. An apparatus on a sheet of paper containing an image to be transmitted, comprising:

a first symbol for designating a first portion of a boundary on said sheet of paper; and

a second symbol for designated the remaining of said boundary on said sheet of paper, said boundary enclosing a portion of said image and designated said portion of said image to be transmitted as clear text.

31. An apparatus as in claim 30, wherein said apparatus is provided on paper coated on one side with an adhesive material, such that said apparatus is to be affixed to said sheet of paper by said adhesive material.

32. An apparatus as in claim 30, wherein said apparatus is generated by a wordprocessor on said sheet of paper.