System and method for viewing message attachments

1. A method for handling secure message attachments for a mobile device, comprising:

receiving at a server a second attachment provided within a secure message, the secure message being enveloped with a secure layer, the secure message itself having been received by the server as a first attachment;

providing the secure message without the second attachment to the mobile device over a wireless network; and

receiving a request to access the second attachment from the mobile device,

wherein in response to the request to access, the method comprises:

looking through the secure layer of the secure message using a session key at the server in order to locate within the secure message the second attachment; and

rendering a first portion of the second attachment by the server in a format for transmission over the wireless network for viewing the first portion by the mobile device without actually transmitting the second attachment to the mobile device, the format being selected by the server to be compatible for viewing on the mobile device based on characteristics of the mobile device,

wherein the request to access the second attachment is automatically provided to the server from the mobile device over the wireless network when either the secure message previously received by the mobile device is opened or when the mobile device receives an indication of a user intent to view the second attachment, and

wherein the method further comprises rendering an additional portion of the second attachment by the server in the format for viewing the additional portion by the mobile device in response to an additional request to access the additional portion of the second attachment.

2. The method of claim 1 , wherein the secure message is structured according to a security scheme such that the secure message is handled as an attachment by the server.

3. The method of claim 2 , wherein the security scheme includes a symmetric key scheme.

4. The method of claim 2 , wherein the security scheme includes an asymmetric key scheme.

5. The method of claim 2 , wherein the security scheme is a Secure Multipurpose Internet Mail Extensions (S/MIME) scheme, and

wherein the server locates the second attachment by locating a MIME field within the secure message.

6. The method of claim 1 , wherein the secure message is structured such that a secure layer has been added to the message and the second attachment.

7. The method of claim 6 , wherein the secure layer acts as an envelope with respect to the message and the second attachment.

8. The method of claim 7 , wherein the secure layer was generated during an encryption operation.

9. The method of claim 8 , wherein the session key is received by the server from the mobile device for use by the server to decrypt the secure message which has been sent from an e-mail sender for routing to the mobile device.

10. The method of claim 7 , wherein the secure layer was generated during a digital signature operation.

11. The method of claim 10 , wherein the secure layer was generated during an encryption operation.

12. The method of claim 1 , wherein the second attachment is selected from the group consisting of: a textual document, word processing document, audio file, image file, and video file.

13. The method of claim 1 , wherein the request from the mobile device to access the second attachment results from a user request about the second attachment.

14. The method of claim 1 , wherein the request from the mobile device includes data to be used by the server to identify the second attachment that is to be provided to the mobile device.

15. The method of claim 1 , wherein the secure message is structured such that a secure layer has been added to the message and the second attachment, wherein the secure layer was generated during an encryption operation, wherein a decryption operation is performed in order to locate within the secure message the second attachment.

16. The method of claim 1 , wherein the secure message has a plurality of attachments.

17. The method of claim 1 , wherein the server provides an indication to the mobile device that the secure message has the second attachment, wherein the indication is used by the mobile device to provide a user indication that the secure message has the second attachment.

18. The method of claim 1 , wherein the second attachment is rendered before being provided to the mobile device.

19. The method of claim 1 , wherein the mobile device is a handheld wireless mobile communications device.

20. The method of claim 1 , wherein the mobile device is a personal digital assistant (PDA).

21. Computer-readable medium capable of causing a mobile device to perform the method of claim 1 .

22. The method of claim 1 wherein the rendering comprises accessing a lookup table to determine the format to use to render the second attachment for viewing by the mobile device, the format being compatible with attachment-viewing software used by the mobile device.

23. The method of claim 22 wherein the rendering further comprises:

transmitting an initial portion of the second attachment for viewing in accordance with the format, and

transmitting additional portions of the second attachment in accordance with the format in response to additional requests from the mobile device.

24. The method of claim 1 wherein when the secure message is encrypted, the processing the secure message includes decrypting the secure message at the server with one or more session keys that were provided by the mobile device in the request to retrieve in order to locate the second attachment within the secure message.

25. An apparatus located at a computer server for handling secure message attachments for a mobile device, wherein the server receives a secure message containing a second attachment, the secure message being enveloped with a secure layer, the secure message having been received by the server as a first attachment, the secure message being provided without the second attachment to the mobile device over a wireless network, the apparatus comprising:

a data store that stores the secure message and the second attachment;

a secure message processing module that looks into the secure message through the secure layer using a session key in order to locate the second attachment;

wherein a first portion of the second attachment is rendered by the server in a format for transmission over the wireless network for viewing by the mobile device over the wireless network without actually transmitting the second attachment after the server receives a request to access the second attachment from the mobile device, the format being selected by the server to be compatible for viewing on the mobile device based on characteristics of the mobile device;

wherein the request to access the second attachment is automatically provided to the server from the mobile device over the wireless network when either the secure message previously received by the mobile device is opened or when the mobile device receives an indication of a user intent to view the second attachment, and

wherein an additional portion of the second attachment is rendered by the server in the format for viewing the additional portion by the mobile device in response to an additional request to access the additional portion of the second attachment.

26. The apparatus of claim 25 , further comprising: a rendering module that renders portions of the second attachment,

wherein the rendering module is configured to:

access a lookup table to determine the format to use to render the second attachment for viewing by the mobile device, the format being compatible with attachment-viewing software used by the mobile device;

transmit an initial portion of the second attachment for viewing in accordance with the format; and

transmit additional portions of the second attachment in accordance with the format in response to additional requests from the mobile device.

27. The apparatus of claim 25 , further comprising:

a decryption processing module to decrypt the secure message with the session key provided by the mobile device in the request to retrieve so that the second attachment can be located within the secure message for the rendering module.

28. An apparatus located at a computer server for handling secure message attachments for a mobile device, comprising:

means for receiving a second attachment provided with a secure message, the secure message being enveloped with a secure layer, the secure message having been received by the server as a first attachment;

means for providing the secure message without the second attachment to the mobile device over a wireless network;

means for receiving a request to access the second attachment from the mobile device;

means for looking through the secure message using a session key in order to locate within the secure message the second attachment in response to the request; and means for rendering a first portion of the second attachment by the server in a format for transmission over the wireless network for viewing by the mobile device without actually transmitting the second attachment in response to the request, the format being selected by the server to be compatible for viewing on the mobile device based on characteristics of the mobile device,

wherein the request to access the second attachment is automatically provided to the server from the mobile device over the wireless network when either the secure message previously received by the mobile device is opened or when the mobile device receives an indication of a user intent to view the second attachment, and

wherein an additional portion of the second attachment is rendered by the server in the format for viewing the additional portion by the mobile device in response to an additional request to access the additional portion of the second attachment.

29. The apparatus of claim 28 , wherein:

the means for rendering comprises a rendering module that renders portions of the second attachment, and

wherein the apparatus further comprises a decryption processing module to decrypt the secure message so that the second attachment can be located within the secure message.

30. The apparatus of claim 29 wherein the rendering module is configured to:

access a lookup table to determine the format to use to render the second attachment for viewing by the mobile device, the format being compatible with attachment-viewing software used by the mobile device;

transmit an initial portion of the second attachment for viewing in accordance with the format; and

transmit additional portions of the second attachment in accordance with the format in response to additional requests from the mobile device, and

wherein the decryption processing module is configured to decrypt the secure message with one or more session keys that were provided by the mobile device in the request to retrieve in order to locate the second attachment within the secure message for the rendering.