System and method for processing messages with encryptable message parts

A non-transitory computer-readable storage medium upon which a plurality of instructions executable by a processor is stored, the instructions for performing 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.

A system for processing a S/MIME e-mail message, the system comprising a first computing device, wherein the S/MIME e-mail message comprises 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, and wherein a microprocessor of the first computing device is configured to:

• identify a plurality of different encryption keys;
• for each of the plurality of e-mail message parts,
• encrypt 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
• associate 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
• provide 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.