SYSTEM AND METHOD FOR PROCESSING ATTACHMENTS TO MESSAGES SENT TO A MOBILE DEVICE

• US 20090061912A1
• Filed: 09/04/2007
• Published: 03/05/2009
• Est. Priority Date: 09/04/2007
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Brown, Michael S., Brown, Michael K., Kirkup, Michael G.
• Granted Patent: US 7,949,355 B2
• Time in Patent Office: Days
• US Class Current: 455/466
• CPC Class Codes: H04L 51/58 Message adaptation for wireless communication

Abstract

A system and method for processing attachments to messages sent to a mobile device is described herein. Embodiments described herein apply to encrypted messages comprising multiple message parts, in which different encryption keys (e.g. session keys) have been used to encrypt the different message parts. In at least one example embodiment, the encrypted session keys for every message content part comprising an attachment is received at the mobile device. In one embodiment, all of the encrypted session keys are stored together in a main message header. The mobile device may then decrypt the encrypted session key associated with a user requested attachment, and transmits the decrypted session key to one or more remote servers in an attachment request for use in decrypting the requested attachment. Data associated with the requested attachment, in decrypted form, is returned to the mobile device.

Claims

1. A method of processing attachments to messages sent to a mobile device, the method comprising:

after a message addressed to a user of the mobile device is received by one or more remote servers, receiving data associated with the message at the mobile device from the one or more remote servers;

wherein the message addressed to the user comprises a plurality of encrypted message content parts, at least one of the plurality of encrypted message content parts comprising an encrypted attachment;

wherein each encrypted message content part has been encrypted using a different one of a plurality of session keys, and each session key has been encrypted using an encryption key associated with the user;

wherein the one or more remote servers are configured to initially withhold transmission of data associated with an attachment to the mobile device, and are configured to subsequently transmit data associated with the attachment to the mobile device if a request therefor is received; and

wherein the data received at the mobile device comprises data identifying an attachment structure for the message, and further comprises at least one encrypted session key; and

outputting the attachment structure at the mobile device.

2. The method of claim 1, wherein the data received at the mobile device comprises an encrypted session key for each encrypted message content part comprising an attachment.

3. The method of claim 1 further comprising:

receiving an attachment request at the mobile device, the attachment request identifying an attachment to the message;

decrypting the encrypted session key for the attachment identified in the attachment request to produce a decrypted session key;

transmitting the decrypted session key with the attachment request from the mobile device to the one or more remote servers;

wherein the one or more remote servers are configured to decrypt the attachment identified in the attachment request using the decrypted session key, and to transmit data associated with the attachment in decrypted form to the mobile device; and

receiving data associated with the attachment identified in the attachment request in decrypted form at the mobile device.

4. The method of claim 1,

wherein the message addressed to the user comprises a main message header;

wherein each encrypted session key for each encrypted attachment has been inserted into the main message header; and

wherein the data associated with the message received at the mobile device comprises data in the main message header.

5. The method of claim 4, wherein the one or more remote servers are configured to retrieve, for the message addressed to the user of the mobile device received by the one or more remote servers, each encrypted session key for each encrypted attachment, and to store each encrypted session key in the main message header.

6. The method of claim 4, wherein at a sender'"'"'s computing device from which the message originates, each encrypted session key for each encrypted attachment has been stored in the main message header.

7. The method of claim 1,

wherein the message addressed to the user comprises a main message header and a message part associated with each encrypted message content part comprising an attachment;

wherein an encrypted session key for each encrypted message content part comprising an attachment has been stored in the associated message part; and

wherein at least one encrypted session key is received at the mobile device.

8. The method of claim 1, wherein the one or more remote servers comprises a message management server.

9. The method of claim 1, where the one or more remote servers comprises an attachment server.

10. The method of claim 1, wherein the message comprises a message formatted in accordance with a PGP Partitioned encoding format.

11. The method of claim 1, wherein the message comprises an e-mail message.

12. The method of claim 1, wherein the message comprises an instant message.

13. The method of claim 1, wherein the message comprises a peer-to-peer message.

14. The method of claim 1, wherein the message addressed to the user comprises a plurality of attachments, each attachment formatted in accordance with a PGP Partitioned encoding format.

15. A computer-readable medium comprising instructions executable on a processor of a computing device for implementing the method of claim 1.

16. A mobile device comprising at least a processor and a memory, wherein the mobile device is configured to execute an application module programmed to perform the method of claim 1.

17. A system for processing attachments to messages, the system comprising:

a mobile device comprising at least a processor and a memory;

wherein one or more remote servers are configured to transmit data associated with a message to the mobile device;

wherein the mobile device is configured to execute an application module programmed to perform the method of claim 1.

18. The system of claim 17, wherein the one or more remote servers comprises a message management server.

19. The system of claim 17, where the one or more remote servers comprises an attachment server.

20. The system of claim 17, wherein the message comprises a message formatted in accordance with a PGP Partitioned encoding format.

21. The system of claim 17, wherein the message comprises an e-mail message.

22. The system of claim 17, wherein the message comprises an instant message.

23. The system of claim 17, wherein the message comprises a peer-to-peer message.