Method and apparatus for tracking and controlling e-mail forwarding of encrypted documents

• US 7,373,330 B1
• Filed: 07/08/2003
• Issued: 05/13/2008
• Est. Priority Date: 07/08/2003
• Status: Active Grant

• Current Assignee: Callahan Cellular LLC (Intellectual Ventures LLC)
• Original Assignee: Copyright Clearance Center, Inc.
• Inventors: Klebe, Skott C.
• Primary Examiner(s): Worjloh; Jalatee
• Application Number:
  US10/614,950
• Time in Patent Office: 1,771 Days
• Field of Search: 705 50- 59, 705 26- 30, 380277-279, 380200-203, 726 26- 30
• US Class Current: 705/51
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: H04L 51/00 User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
• CPC Class Codes: H04L 51/234 for tracking messages
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload

Abstract

In response to a request from a content server to forward an encrypted document to a recipient user, a forwarding engine in the content server prepares an e-mail message that contains a link to the document publisher and an identifier for the document. Upon receiving the e-mail, the recipient user can log onto a content server in the publisher and the publisher content server resolves the link, downloads a secure viewer program and an encrypted version of the requested document to the viewer program. Subsequently, the secure viewer program requests a decryption key for the encrypted document and decrypts the document. The recipient user can then view the document content in secure viewer but cannot copy or print the document without permission from the publisher.

Claims

1. A method for allowing a user and a recipient user to securely review content of a document generated by a document publisher and downloaded to a content server accessible to the user, but not to the recipient user, the method comprising:

(a) in response to a request from the user, preparing in the content server, an e-mail message that contains a link to the publisher and an identifier for the document, but does not contain the document content;

(b) using the content server to send the e-mail message to the recipient user wherein, upon receiving the e-mail, the recipient user logs onto a forwarding server at the document publisher, the forwarding server being different from the content server;

(c) receiving and resolving the link at the publisher and downloading from the forwarding server a secure viewer program to the recipient user and an encrypted version of the requested document content to the secure viewer program;

(d) requesting a decryption key for the encrypted document from the forwarding server with the secure viewer program; and

(e) decrypting the encrypted document content and displaying the document content in the secure viewer program.

2. The method of claim 1 wherein step (a) comprises making the request to forward the encrypted document to the recipient user with a secure viewer running in a browser.

3. The method of claim 1 wherein the link in the e-mail message contains information identifying the sender of the e-mail, the recipient of the e-mail and the encrypted document.

4. The method of claim 3 wherein the information is inserted into the URL of the link to the publisher.

5. The method of claim 3 wherein step (a) comprises encrypting the identifying information in the e-mail message.

6. The method of claim 5 wherein step (a) comprises encrypting the information with a public key of a public/private key pair assigned of the publisher.

7. The method of claim 1 wherein step (b) comprises opening, in a computer of the recipient user, a browser in response to a selection of the link by the recipient user and navigating to the forwarding server.

8. The method of claim 7 wherein step (c) comprises downloading a secure viewer program into the browser in the recipient user'"'"'s computer.

9. The method of claim 1 wherein step (c) comprises downloading a document identifier to the secure viewer program running in the recipient user'"'"'s computer.

10. The method of claim 9 wherein step (d) comprises using the document identifier to request a decryption key from the forwarding server.

11. The method of claim 10 wherein step (d) further comprises returning the decryption key from the forwarding server to the secure viewer program in response to the document identifier.

12. The method of claim 1 further comprising logging the information in the e-mail including the sender, the recipient and the document identifier by the forwarding server.

13. The method of claim 1 wherein the link maintains a count of the number of times it has been selected.

14. The method of claim 13 wherein the link is a one-time link.

15. Apparatus for allowing a user and a recipient user to securely review content of a document generated by a document publisher and downloaded to a content server accessible to the user, but not to the recipient user, the apparatus comprising:

means responsive to a request from the user for preparing in the content server, an e-mail message that contains a link to the publisher and an identifier for the document, but does not contain the document content;

means in the content server for sending the e-mail message to the recipient user wherein, upon receiving the e-mail, the recipient user logs onto a forwarding server at the document publisher, the forwarding server being different from the content server;

means for receiving and resolving the link at the publisher and downloading from the forwarding server a secure viewer program to the recipient user and an encrypted version of the requested document content to the secure viewer program;

means for requesting a decryption key for the encrypted document from the forwarding server with the secure viewer program; and

means for decrypting the encrypted document content and displaying the document content in the secure viewer program.

16. The apparatus of claim 15 wherein the request to forward the encrypted document to the recipient user is made with a secure viewer running in a browser.

17. The apparatus of claim 15 wherein the link in the e-mail message contains information identifying the sender of the e-mail, the recipient of the e-mail and the encrypted document.

18. The apparatus of claim 17 wherein the information is inserted into the URL of the link to the publisher.

19. The apparatus of claim 17 further comprising means for encrypting the identifying information in the e-mail message.

20. The apparatus of claim 19 wherein the means for encrypting the identifying information comprises means for encrypting the information with a public key of a public/private key pair assigned of the publisher.

21. The apparatus of claim 15 further comprising means for opening, in a computer of the recipient user, a browser in response to a selection of the link by the recipient user and means for using the browser to navigate to the forwarding server.

22. The apparatus of claim 21 wherein the means for downloading a secure viewer program comprises means for downloading a secure viewer program into the browser in the recipient user'"'"'s computer.

23. The apparatus of claim 15 wherein the means for downloading an encrypted version of the requested document to the secure browser program comprises means for downloading a document identifier to the secure viewer program running in the recipient user'"'"'s computer.

24. The apparatus of claim 23 wherein the means for requesting a decryption key comprises means for using the document identifier to request a decryption key from the forwarding server.

25. The apparatus of claim 24 wherein the means for requesting a decryption key further comprises means for returning the decryption key from the forwarding server to the secure viewer program in response to the document identifier.

26. The apparatus of claim 15 further comprising means for logging the information in the e-mail including the sender, the recipient and the document identifier by the forwarding server.

27. The apparatus of claim 15 wherein the link maintains a count of the number of times it has been selected.

28. The apparatus of claim 27 wherein the link is a one-time link.

29. A computer program product for allowing a user and a recipient user to securely review content of a document generated by a document publisher and downloaded to a content server accessible to the user, but not to the recipient user, the computer program product comprising a computer storage medium having computer readable program code thereon, including:

program code operable in response to a request from the user, for preparing in the content server, an e-mail message that contains a link to the publisher and an identifier for the document, but does not contain the document content;

program code for controlling the content server to send the e-mail message to the recipient user wherein, upon receiving the e-mail, the recipient user logs onto a forwarding server at the document publisher, the forwarding server being different from the content server;

program code for receiving and resolving the link at the publisher and downloading from the forwarding server a secure viewer program to the recipient user and an encrypted version of the requested document content to the secure viewer program;

program code for requesting a decryption key for the encrypted document from the forwarding server with the secure viewer program; and

program code for decrypting the encrypted document content and displaying the document content in the secure viewer program.

30. The computer program product of claim 29 wherein the program code for preparing an e-mail message comprises a secure viewer program running in a browser that makes the request to forward the encrypted document to the recipient user.

31. The computer program product of claim 29 wherein the link in the e-mail message contains information identifying the sender of the e-mail, the recipient of the e-mail and the encrypted document.

32. The computer program product of claim 31 wherein the information is inserted into the URL of the link to the publisher.

33. The computer program product of claim 31 wherein the program code for preparing an e-mail message comprises program code for encrypting the identifying information in the e-mail message.

34. The computer program product of claim 33 wherein the program code for preparing an e-mail message comprises program code for encrypting the information with a public key of a public/private key pair assigned of the publisher.

35. The computer program product of claim 29 wherein the program code for sending the e-mail message to the recipient user comprises program code for opening, in a computer of the recipient user, a browser in response to a selection of the link by the recipient user and navigating to the forwarding server.

36. The computer program product of claim 35 wherein the program code for downloading a secure viewer program to the recipient user comprises program code for downloading a secure viewer program into the browser in the recipient user'"'"'s computer.

37. The computer program product of claim 29 wherein the program code for downloading a secure viewer program to the recipient user comprises program code for downloading a document identifier to the secure viewer program running in the recipient user'"'"'s computer.

38. The computer program product of claim 37 wherein the program code for requesting a decryption key for the encrypted document comprises program code for using the document identifier to request a decryption key from the forwarding server.

39. The computer program product of claim 38 wherein the program code for requesting a decryption key for the encrypted document further comprises program code for returning the decryption key from the forwarding server to the secure viewer program in response to the document identifier.

40. The computer program product of claim 29 further comprising program code for logging the information in the e-mail including the sender, the recipient and the document identifier by the forwarding server.

41. The computer program product of claim 29 wherein the link maintains a count of the number of times it has been selected.

42. The computer program product of claim 41 wherein the link is a one-time link.