Secure message handling on a mobile device

• US 8,452,013 B2
• Filed: 07/31/2007
• Issued: 05/28/2013
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Brown, Michael S., Brown, Michael K.
• Primary Examiner(s): Chea, Philip
• Assistant Examiner(s): Traore, Fatoumata
• Application Number:
  US11/831,285
• Publication Number:
  US 20090034729A1
• Time in Patent Office: 2,128 Days
• Field of Search: None
• US Class Current: 380/270
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• 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 51/58 Message adaptation for wireless communication
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

Systems, methods, and software for providing digital security to a child message transmitted from a mobile device to a messaging server, where the mobile device typically does not transmit the parent message with the child message to the messaging server. Whether to apply digital security, such as encryption or a digital signature, or both, is determined, and if the mobile device does not include a complete copy of a parent message for insertion into the child message, the mobile device selectively downloads the parent message from the messaging server prior to the computation of a digital signature or prior to encryption. The systems and methods may also provide a check of the child message size, when the child message includes inserted parent content, to ensure that the child message does not exceed any prescribed limits on message size.

Claims

1. A method implemented at a mobile device for providing digital security to a message transmitted from a mobile device, the method comprising:

initiating the generation of a message to be transmitted, the message to be transmitted being associated with a previously received message, only a portion of the previously received message being stored at the mobile device;

determining that digital security comprising one or more of encryption and a digital signature is to be applied to the message to be transmitted from the mobile device;

after initiating the generation of the message to be transmitted and determining that digital security is to be applied to the message to be transmitted, the mobile device obtaining a complete copy of the previously received message by downloading the complete copy while the message to be transmitted is being generated;

appending the previously received message thus obtained to the message to be transmitted;

applying the digital security to the message to be transmitted comprising the appended previously received message; and

transmitting the message to be transmitted from the mobile device.

2. The method of claim 1, wherein the digital security comprises the digital signature.

3. The method of claim 1, wherein the digital security comprises encryption.

4. The method of claim 1, wherein the message to be transmitted comprises a reply to the previously received message.

5. The method of claim 1, wherein the message to be transmitted comprises a message that forwards the previously received message to one or more recipients.

6. The method of claim 1, wherein the portion of said previously received message comprises a first initially received chunk of the previously received message.

7. The method of claim 6, wherein the first initially received chunk comprises a header of the previously received message.

8. The method of claim 1, wherein generating the message to be transmitted comprises composition of the message at the mobile device.

9. The method of claim 1, wherein the digital security complies with the S/MIME standard.

10. The method of claim 1, wherein the digital security complies with a PGP standard.

11. The method of claim 1, further comprising requesting an instruction to obtain the complete copy of the previously received message and, in response to said instruction, applying digital security to the message to be transmitted after appending said previously received message to the message to be transmitted.

12. The method of claim 1, further comprising:

determining whether a body of the message to be transmitted exceeds a predetermined size limit; and

selectively truncating the body of the message to be transmitted prior to transmission of said message, if the body of said message exceeds said size limit,

wherein the message to be transmitted is associated with a digital signature.

13. The method of claim 12, wherein determining whether the body of the message exceeds the predetermined size limit and selectively truncating the body of the message prior to transmission of the message comprises requesting an instruction relating to truncation of the message and, in response to said instruction, disassociating the digital signature from the message and truncating the message.

14. The method of claim 13, wherein requesting the instruction relating to truncation of the message further comprises:

recomputing a digital signature for the truncated message; and

associating the recomputed digital signature with the truncated message.

15. The method of claim 1, wherein initiating the generation of the message to be transmitted comprises receiving input at the mobile device to generate a new message.

16. The method of claim 1, wherein the generation of the message to be transmitted comprises receiving input for adding content to the message to be transmitted.

17. The method of claim 1, wherein obtaining a complete copy of the previously received message comprises receiving an entirety of a body of the previously received message.

18. A mobile device for providing digital security to a message comprising a processor configured to:

initiate the generation of a message to be transmitted, the message to be transmitted being associated with a previously received message, only a portion of the previously received message being stored at the mobile device;

determine that digital security comprising one or more of encryption and a digital signature is to be applied to the message to be transmitted from the mobile device;

after initiating the generation of the message to be transmitted and determining that digital security is to be applied to the message to be transmitted, obtain a complete copy of the previously received message by downloading while the message to be transmitted is being generated;

append the previously received message thus obtained to the message to be transmitted;

apply the digital security to the message to be transmitted comprising the appended previously received message; and

transmit the message to be transmitted.

19. The mobile device of claim 18, wherein the mobile device comprises a smartphone.

20. The mobile device of claim 18, wherein the mobile device comprises a personal computer.

21. The mobile device of claim 18, wherein the message to be transmitted comprises a reply to the previously received message.

22. The mobile device of claim 18, wherein the message to be transmitted comprises a message that forwards the previously received message to one or more recipients.

23. The mobile device of claim 18, wherein the said portion of said previously received message comprises a first initially received chunk of said previously received message.

24. The mobile device of claim 18, wherein the first initially received chunk comprises a header of the previously received message.

25. The mobile device of claim 18, wherein the digital security complies with either the S/MIME standard or the PGP standard.

26. The mobile device of claim 18, wherein the processor is further configured to:

determine whether a body of the message to be transmitted exceeds a predetermined size limit, and to selectively truncate the body of the message prior to transmission of the message, if said body of the message exceeds said size limit,

wherein the message is associated with a digital signature.

27. The mobile device of claim 26, wherein the processor is further configured to request an instruction relating to truncation of the body of the message and, in response to said instruction, disassociate the digital signature from the message to be transmitted and truncate the message to be transmitted.

28. The mobile device of claim 27, wherein the processor is further configured to:

recompute a digital signature for the truncated message; and

associate the recomputed digital signature with the truncated message.

29. The mobile device of claim 18, wherein the mobile device is LEMONADE compliant.

30. The mobile device of claim 18, wherein obtaining a complete copy of the message comprises receiving an entirety of a body of the previously received message.

31. The mobile device of claim 18, wherein initiating the generation of the message to be transmitted comprises receiving input at the mobile device to generate a new message.

32. The mobile device of claim 18, wherein the generation of the message to be transmitted comprises receiving input for adding content to the message to be transmitted.

33. A non-transitory computer-readable medium comprising code executable by a computing device for causing the computing device to:

initiate the generation of a message to be transmitted, the message to be transmitted being associated with a previously received message, only a portion of the previously received message being stored at the mobile device;

determine that digital security comprising one or more of encryption and a digital signature is to be applied to the message to be transmitted from the mobile device;

after initiating the generation of the message to be transmitted and determining that digital security is to be applied to the message to be transmitted, obtain a complete copy of the previously received message by downloading the complete copy while the message to be transmitted is being generated;

append the previously received message into the message to be transmitted;

apply the digital security to the message to be transmitted comprising the appended previously received message; and

transmit the message to be transmitted.

34. A method implemented at a mobile device for providing digital security to a message transmitted from a mobile device, the method comprising:

initiating the generation of a message to be transmitted associated with a previously received message, only a portion of the previously received message being stored at the mobile device;

determining that a digital signature is to be applied to the message to be transmitted;

obtaining a complete copy of the previously received message by download after the determining and while the message to be transmitted is being generated;

inserting content from the complete copy of the previously received message into the message;

determining whether a body of the message to be transmitted comprising the inserted content exceeds a predetermined size limit, and truncating the body prior to transmission of the message if the body exceeds the size limit;

applying the digital signature to the truncated message; and

transmitting the message.

35. The method of claim 34, further comprising:

after inserting the content but before determining whether the body of the message to be transmitted comprising the inserted content exceeds the predetermined size limit, applying an initial digital signature to the message to be transmitted comprising the inserted content,

the digital signature applied to the truncated message thus being recomputed after the truncating.

36. A method implemented at a mobile device for providing digital security to a message transmitted from a mobile device, the method comprising:

initiating the generation of a message to be transmitted, the message to be transmitted being associated with a previously received message, only a portion of the previously received message being stored at the mobile device;

determining that encryption is to be applied to the message to be transmitted from the mobile device;

obtaining a complete copy of the previously received message by download while the message to be transmitted is being generated;

appending the previously received message to the message to be transmitted;

encrypting the message to be transmitted comprising the appended previously received message; and

transmitting the message.