Patent ID: 8542824

Claim:
A method of processing a S/MIME e-mail message at a first computing device, the S/MIME e-mail message comprising a plurality of e-mail message parts, each of the plurality of e-mail message parts containing one version of a plurality of different versions of a message text, the method comprising: identifying a plurality of different encryption keys; for each of the plurality of e-mail message parts, encrypting the version of the message text of the e-mail message part using an encryption key selected from the plurality of different encryption keys, and associating with the e-mail message part, an encryption key identifier that identifies the encryption key used to encrypt the version of the message text of the e-mail message part; and providing within the S/MIME e-mail message, the encryption key identifiers associated with the plurality of e-mail message parts; wherein at least one of the plurality of different encryption keys used to encrypt the plurality of different versions of the message text of the plurality of e-mail message parts, or encryption key identifiers for locating at a second computing device the plurality of different encryption keys that will decrypt the plurality of different versions of the message text of the plurality of e-mail message parts, is further provided within the S/MIME e-mail message, arranged by the encryption key identifiers and stored in at least one e-mail message part that is separate from the plurality of e-mail message parts containing the plurality of different versions of the message text.