Method, system, and program product for generating and validating digital signatures

• US 7,975,143 B2
• Filed: 06/12/2006
• Issued: 07/05/2011
• Est. Priority Date: 06/12/2006
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Trakhtenberg, Vladimir, Boyer, John M.
• Primary Examiner(s): TRAN, ELLEN C
• Application Number:
  US11/423,572
• Publication Number:
  US 20070288393A1
• Time in Patent Office: 1,849 Days
• Field of Search: 726/10, 713/176, 713/177
• US Class Current: 713/176
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2221/2147 Locking files
• CPC Class Codes: G06Q 20/3821 Electronic credentials
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/68 Special signature format, e.g. XML format
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

Under the present invention, an electronic document is accessed. Each user interface control (UIC) in the electronic document is confirmed to be operationally classified as signed or unsigned by a given digital signature based on whether the UIC is associated with a data node that is signed by the digital signature. It is then determined whether the signed UIC is visible. A token representing a geometric location of the visible signed UIC within a visual representation of the electronic document and a relative location of the visible signed UIC to other visible signed UICs in the electronic document is then recorded. However, if the UIC is contained within any hierarchic UICs, the location thereof is first converted to the geometric location within the visual representation prior to recording the token. The digital signature can then be generated and/or validated unless a UIC overlap and/or layout violation is committed.

Claims

1. A method for generating digital signatures, comprising:

accessing an electronic document having at least one user interface control (UIC) using a computer device;

confirming, for each UIC, whether the UIC is operationally classified as signed by a digital signature being generated based on whether the UIC is associated with a data node that is included in the signed material of the signature;

determining, for each signed UIC, whether the signed UIC is visible by combining local visibility information with a hierarchic UIC'"'"'s visibility information, wherein said hierarchic UIC contains the signed UIC;

converting the location of each visible UIC contained within any hierarchic UIC from a geometric location within any containing hierarchic UIC to the geometric location within the visual representation;

recording, after the converting step, within a cryptographically protected portion of the digital signature a layout token, wherein the layout token represents a geometric size of each visible signed UIC within a visual representation of the electronic document and a location of each visible signed UIC relative to other visible signed UICs in the electronic document; and

generating the digital signature unless a UIC overlap violation is committed.

2. The method of claim 1, further comprising determining if a UIC overlap violation is committed, wherein a UIC overlap violation comprises one signed UIC and one unsigned UIC for which:

the signed UIC is not a hierarchic UIC or the unsigned UIC is not part of the signed hierarchic UIC; and

geometric regions on the visual representation occupied by the signed UIC and the unsigned UIC intersect by more than a predetermined overlap tolerance.

3. The method of claim 2, further comprising generating a new digital signature in an electronic document that contains other digital signatures, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the new digital signature being generated, and without regard for the signature information from any pre-existing digital signatures in the electronic document.

4. The method of claim 3, further comprising validating the digital signature by determining whether any signed or unsigned UIC commits at least one of:

a UIC layout violation or a UIC overlap violation.

5. The method of claim 4, further comprising determining if a UIC layout violation is committed by:

determining whether each signed UIC is visible by combining local visibility information with visibility information of any hierarchic UIC containing the UIC;

converting the location of each visible signed UIC from a geometric location within any containing hierarchic UIC to a geometric location within a visual representation of the electronic document;

recording a validation token representing a geometric size of each visible signed UIC within a visual representation of the electronic document and a location of each visible signed UIC relative to other visible signed UICs in the electronic document; and

comparing the validation token to the layout token to determine if a predetermined layout tolerance is exceeded.

6. The method of claim 5, further comprising determining a UIC layout violation is committed if any switch hierarchic UIC of the electronic document changes cases after generation of the digital signature, except those switch hierarchic UICs that are deemed mutable by notations in at least one of the electronic document or the digital signature.

7. The method of claim 6, further comprising validating a particular digital signature in an electronic document that contains one or more other digital signatures, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the particular digital signature being validated, and without regard to signature information from other digital signatures in the electronic document.

8. A system for generating digital signatures, comprising:

a computer device including;

a system for accessing an electronic document having at least one user interface control (UIC);

a system for confirming, for each UIC, whether the UIC is operationally classified as signed by a digital signature being generated based on whether the UIC is associated with a data node that is included in the signed material of the signature;

a system for determining, for each signed UIC, whether the signed UIC is visible by combining local visibility information with a hierarchic UIC'"'"'s visibility information, wherein said hierarchic UIC contains the signed UIC;

a system for converting the location of each visible UIC contained within any hierarchic UIC from a geometric location within any containing hierarchic UIC to the geometric location within the visual representation;

a system for recording, after the converting step, within a cryptographically protected portion of the digital signature a layout token, wherein the layout token represents a geometric size of each visible signed UIC within a visual representation of the electronic document and a location of each visible signed UIC relative to other visible signed UICs in the electronic document; and

a system for generating the digital signature unless a UIC overlap violation is committed.

9. The system of claim 8, further comprising a system for determining if a UIC overlap violation is committed, wherein a UIC overlap violation comprises one signed UIC and one unsigned UIC for which:

the signed UIC is not a hierarchic UIC or the unsigned UIC is not part of the signed hierarchic UIC; and

geometric regions on the visual representation occupied by the signed UIC and the unsigned UIC intersect by more than a predetermined overlap tolerance.

10. The system of claim 9, wherein the system for generating generates a new digital signature in an electronic document that contains other digital signatures, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the new digital signature being generated, and without regard to signature information from any pre-existing digital signatures in the electronic document.

11. The system of claim 10, further comprising a system for validating the digital signature by determining whether any signed or unsigned UIC commits at least one of:

a UIC layout violation or a UIC overlap violation.

12. The system of claim 11, further comprising a system for determining if a UIC layout violation is committed by:

determining whether each signed UIC is visible by combining local visibility information with visibility information of any hierarchic UICs containing the UIC;

converting the location of each visible signed UIC from a geometric location within any containing hierarchic UICs to a geometric location within a visual representation of the electronic document;

recording a validation token representing a geometric size of each signed UIC within a visual representation of the electronic document and a location of each signed UIC relative to an other visible signed UICs in the electronic document;

ad

comparing the validation token to the layout token to determine if a predetermined layout tolerance is exceeded.

13. The system of claim 12, further comprising a system for determining a UIC layout violation is committed if any switch hierarchic UIC of the electronic document changes cases after generation of the digital signature, except those switch hierarchic UICs that are deemed mutable by notations in the electronic document or the digital signature.

14. The system of claim 13, further comprising a system for validating a particular digital signature in an electronic document that contains one or more other digital signatures generated, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the particular digital signature being validated, and without regard for the signature information from other digital signatures in the electronic document.

15. A program product stored on a non-transitory computer readable storage medium for generating digital signatures, the computer readable medium comprising computer program code for causing a computer system to perform the following functions:

accessing an electronic document having at least one user interface control (UIC);

confirming, for each UIC, whether the UIC is operationally classified as signed by a digital signature being generated based on whether the UIC is associated with a data node that is included in the signed material of the signature;

determining, for each signed UIC, whether the signed UIC is visible by combining local visibility information with a hierarchic UIC'"'"'s visibility information, wherein said hierarchic UIC contains the signed UIC;

converting the location of each visible UIC contained within any hierarchic UIC from a geometric location within any containing hierarchic UIC to the geometric location within the visual representation;

recording, after the converting step, within a cryptographically protected portion of the digital signature a layout token, wherein the layout token represents a geometric size of each visible signed UIC within a visual representation of the electronic document and a location of each visible signed UIC relative to other visible signed UICs in the electronic document; and

generating the digital signature unless a UIC overlap violation is committed.

16. The program product of claim 15, wherein the non-transitory computer readable storage medium further comprises program code to cause the computer system to perform the following additional function:

determining if a UIC overlap violation is committed, wherein a UIC overlap violation comprises one signed UIC and one unsigned UIC for which;

the signed UIC is not a hierarchic UIC or the unsigned UIC is not part of the signed hierarchic UIC; and

geometric regions on the visual representation occupied by the signed UIC and the unsigned UIC intersect by more than a predetermined overlap tolerance.

17. The program product of claim 16, wherein the non-transitory computer readable storage medium further comprises program code to cause the computer system to perform the following additional function:

generating a new digital signature in an electronic document that contains other digital signatures, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the new digital signature being generated, and without regard for the signature information from any pre-existing digital signatures in the electronic document.

18. The program product of claim 17, wherein the non-transitory computer readable storage medium further comprises program code to cause the computer system to perform the following additional function:

validating the digital signature by determining whether any signed or unsigned UIC commits at least one of;

a UIC layout violation or a UIC overlap violation.

19. The program product of claim 18, wherein the non-transitory computer readable storage medium further comprises program code to cause the computer system to perform the following additional function:

determining if a UIC layout violation is committed by;

determining whether each signed UIC is visible by combining local visibility information with visibility information of any hierarchic UIC containing the UIC;

converting the location of each visible signed UIC from a geometric location within any containing hierarchic UIC to a geometric location within a visual representation of the electronic document;

recording a validation token representing a geometric size of each signed UIC within a visual representation of the electronic document and a location of each signed UIC relative to other visible signed UICs in the electronic document; and

comparing the validation token to the layout token to determine if a predetermined layout tolerance is exceeded.

20. The program product of claim 19, wherein the non-transitory computer readable storage medium further comprises program code to cause the computer system to perform the following additional function:

determining a UIC layout violation is committed if any switch hierarchic UIC of the electronic document changes cases after generation of the digital signature, except those switch hierarchic UICs that are deemed mutable by notations in the electronic document or the digital signature.

21. The program product of claim 20, wherein the non-transitory computer readable storage medium further comprises program code to cause the computer system to perform the following additional function:

validating a particular digital signature in an electronic document that contains one or more other digital signatures, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the particular digital signature being validated, and without regard to signature information from other digital signatures in the electronic document.

22. A method for deploying a system for generating digital signatures, comprising:

providing a computer infrastructure being configured to;

access an electronic document having at least one user interface control (UIC);

confirm, for each UIC, whether the UIC is operationally classified as signed by a digital signature being generated based on whether the UIC is associated with a data node that is included in the signed material of the signature;

determine, for each signed UIC, whether the signed UIC is visible by combining local visibility information with a hierarchic UIC'"'"'s visibility information, wherein said hierarchic UIC contains the signed UIC;

convert the location of each visible UIC contained within any hierarchic UIC from a geometric location within any containing hierarchic UIC to the geometric location within the visual representation;

record, after the convert step, within a cryptographically protected portion of the digital signature a layout token, wherein the layout token represents a geometric size of each visible signed UIC within a visual representation of the electronic document and a location of each visible signed UIC relative to other visible signed UICs in the electronic document; and

generate the digital signature unless a UIC overlap violation is committed.

23. The method of claim 22, wherein the computer infrastructure is further operable to:

determine if a UIC overlap violation is committed, wherein a UIC overlap violation comprises one signed UIC and one unsigned UIC for which;

the signed UIC is not a hierarchic UIC or the unsigned UIC is not part of the signed hierarchic UIC; and

geometric regions on the visual representation occupied by the signed UIC and the unsigned UIC intersect by more than a predetermined overlap tolerance.

24. The method of claim 23, wherein the computer infrastructure is further operable to:

generate a new digital signature in an electronic document that contains other digital signatures, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the new digital signature being generated, and without regard for the signature information from any pre-existing digital signatures in the electronic document.

25. The method of claim 24, wherein the computer infrastructure is further operable to validate the digital signature by determining whether any signed or unsigned UIC commits at least one of:

a UIC layout violation or a UIC overlap violation.

26. The method of claim 25, wherein the computer infrastructure is further operable to determine if a UIC layout violation is committed by:

determining whether each signed UIC is visible by combining local visibility information with visibility information of any hierarchic UIC containing the UIC;

converting the location of each visible signed UIC from a geometric location within any containing hierarchic UIC to a geometric location within a visual representation of the electronic document;

recording a validation token representing a geometric size of each signed UIC within a visual representation of the electronic document and a location of each signed UIC relative to other visible signed UICs in the electronic document; and

comparing the validation token to the layout token to determine if a predetermined layout tolerance is exceeded.

27. The method of claim 26, wherein the computer infrastructure is further operable to determine a UIC layout violation is committed if any switch hierarchic UIC of the electronic document changes cases after generation of the digital signature, except those switch hierarchic UICs that are deemed mutable by notations in the electronic document or the digital signature.

28. The method of claim 27, wherein the computer infrastructure is further operable to validate a particular digital signature in an electronic document that contains one or more other digital signatures, wherein each UIC is confirmed to be operationally classified as signed or unsigned for the particular digital signature being validated, and without regard to signature information from other digital signatures in the electronic document.