Method and system for sending secure messages

• US 20070260876A1
• Filed: 05/05/2006
• Published: 11/08/2007
• Est. Priority Date: 05/05/2006
• Status: Abandoned Application

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Brown, Michael, Klrkup, Michael
• Application Number:
  US11/418,176
• Publication Number:
  US 20070260876A1
• Time in Patent Office: Days
• US Class Current: 713/156
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 9/3265 using certificate chains, trees or paths; Hierarchical trust model

Abstract

A user device and method for securely sending messages to a recipient. The device and method initiate a search for a certificate needed to encrypt a message to a particular recipient prior to receiving a send instruction from the user. The device may determine when a user changes the recipients for the message and, as the user composes the message, determine whether the requisite certificates are stored locally on the device or need to be obtained from a remote source. If the certificates required are not on the device, then a search of the remote source is initiated. The detection of changes to the recipient list and the initiation of any required searches occurs prior to receipt of a send instruction from the user.

Claims

1. A method for securely sending messages from a sending device to a recipient over a computer network, the sending device including a messaging application for composing a message to one or more recipients, each recipient having an associated certificate, each certificate including a recipient-specific public key for use by the sending device in encrypting the message for transmission to the associated recipient, the sending device including a memory storing one or more certificates in a key store, the method comprising steps of:

detecting input of a new recipient in an address field of the message;

determining that the key store does not include a valid certificate for said new recipient;

initiating a search of a remote source for said valid certificate through said computer network; and

downloading said valid certificate, including a public key for said new recipient,

wherein said steps of detecting, determining, and initiating are performed prior to receiving a user instruction to send the message.

2. The method claimed in claim 1, wherein said step of detecting includes detecting that said address field is active and detecting user input to said address field.

3. The method claimed in claim 1, wherein the messaging application includes a user interface having a compose message view and wherein said user interface includes a plurality of fields, and said plurality of fields includes said address field, and wherein said step of detecting includes detecting that said address field is designated as an active field and then detecting a change in designation such that another of said plurality of fields is said active field.

4. The method claimed in claim 3, wherein said plurality of fields includes two or more address fields and wherein said another of said plurality of fields excludes said address fields.

5. The method claimed In claim 1, wherein said step of detecting input of said new recipient includes reading a current list of recipients from said address field, comparing said current list of recipients to a stored previous list, and saving said current list of recipients as said stored previous list.

6. The method claimed in claim 1, wherein said step of Initiating includes determining whether an active search is in progress for said valid certificate and, if not, initiating said search.

7. The method claimed in claim 1, further including a step of determining if an active search is in progress for a certificate corresponding to a recipient removed from said address field and, if so, issuing an instruction to cancel said active search.

8. The method claimed in claim 1, further including steps of encrypting the message with said public key and transmitting the encrypted message, wherein said steps of encrypting and transmitting are performed in response to receipt of said user instruction to send.

9. A user device for sending secure messages to a recipient over a computer network, the user device comprising:

a display for rendering a user Interface showing a message, the user interface including an address field of the message;

a user input device for receiving user input;

a memory, including a key store for storing one or more certificates;

a processor for interacting with said display, said memory, and said user input device;

a messaging application executable by said processor for composing and sending the message;

a search triggering component executable by said processor for detecting input of a new recipient in said address field, for determining that said key store does not contain a valid certificate for said new recipient, and for initiating a search for said valid certificate; and

a certificate retrieval module executable by said processor for searching a remote source for said valid certificate and downloading said valid certificate, including a public key for said new recipient,

wherein said search triggering component is adapted to instruct said certificate retrieval module to initiate a search for said valid certificate prior to receipt of a user instruction to send the message when said search triggering component determines that said key store does not contain said valid certificate.

10. The user device claimed in claim 9, wherein said search triggering component is adapted to detect that said address field is active and detect user input to said address field.

11. The user device claimed in claim 9, wherein said user interface includes a plurality of fields, and said plurality of fields includes said address field, and wherein said search triggering component is adapted to detect that said address field is designated as an active field and then detect a change in designation such that another of said plurality of fields is said active field.

12. The user device claimed in claim 11, wherein said plurality of fields includes two or more address fields and wherein said another of said plurality of fields excludes said address fields.

13. The user device claimed in claim 9, wherein said search triggering component is adapted to read a current list of recipients from said address field, compare said current list of recipients to a stored previous list, and save said current list of recipients as said stored previous list.

14. The user device claimed in claim 9, wherein said search triggering component includes a component for determining whether an active search is in progress for said valid certificate and, if not, initiating said search.

15. The user device claimed in claim 9, wherein said search triggering component includes a component for determining if an active search is in progress for a certificate corresponding to a recipient removed from said address field and, if so, issuing an instruction to cancel said active search.

16. The user device claimed in claim 9, wherein said messaging application is adapted to encrypt the message with said public key and transmit the encrypted message in response to receipt of said user instruction to send.

17. The user device claimed in claim 9, wherein said user device comprises a handheld mobile device and wherein the computer network includes a wireless network.

18. A computer-readable program for securely sending messages from a sending device to a recipient over a computer network, the sending device including a messaging application for composing a message to one or more recipients, each recipient having an associated certificate, each certificate including a recipient-specific public key for use by the sending device in encrypting the message for transmission to the associated recipient, the sending device including a memory storing one or more certificates in a key store, the computer-readable program comprising a computer-readable medium having recorded thereon computer-executable instructions, said computer-executable instructions comprising:

instructions for detecting input of a new recipient in an address field of the message;

instructions for determining that the key store does not include a valid certificate for said new recipient;

instructions for initiating a search of a remote source for said valid certificate through said computer network; and

instructions for downloading said valid certificate, including a public key for said new recipient,

wherein said instructions for detecting, determining, and initiating are executed prior to receiving a user command to send the message.

19. The computer-readable program claimed in claim 18, wherein said instructions for detecting include instructions for detecting that said address field is active and detecting user input to said address field.

20. The computer-readable program claimed in claim 18, wherein the messaging application includes a user interface having a compose message view and wherein said user interface includes a plurality of fields, and said plurality of fields includes said address field, and wherein said instructions for detecting include instructions for detecting that said address field is designated as an active field and then detecting a change in designation such that another of said plurality of fields is said active field.

21. The computer-readable program claimed in claim 20, wherein said plurality of fields includes two or more address fields and wherein said another of said plurality of fields excludes said address fields.

22. The computer-readable program claimed in claim 18, wherein said instructions for detecting input of said new recipient includes instructions for reading a current list of recipients from said address field, instructions for comparing said current list of recipients to a stored previous list, and instructions for saving said current list of recipients as said stored previous list.

23. The computer-readable program claimed in claim 18, wherein said instructions for initiating include instructions for determining whether an active search is in progress for said valid certificate and, if not, initiating said search.

24. The computer-readable program claimed in claim 18, further including instructions for determining if an active search is in progress for a certificate corresponding to a recipient removed from said address field and, if so, issuing an instruction to cancel said active search.

25. The computer-readable program claimed in claim 18, further including instructions for encrypting the message with said public key and transmitting the encrypted message, wherein said instructions for encrypting and transmitting are executed in response to receipt of said user command to send.