Patent ID: 8423773

Claim:
A multimedia message system for receiving/sending a multimedia message, comprising: a wireless LAN; and a multimedia messaging service (MMS) gateway performing: receiving/sending the multimedia message to/from a MMS user device via the wireless LAN; and encrypting the multimedia message by: issuing a certificate to the MMS user device; sending a session ID and a master key encrypted by the MMS gateway's private key to the MMS user device in response to a request of said MMS user device having the certificate; generating a shared secret key using an algorithm combining the master key with the MMS user device's phone number and the session ID; and encrypting the multimedia message using the shared secret key; wherein the MMS user device, upon receipt of the encrypted MMS message: decodes the master key received from the MMS gateway; and generates the shared secret key using the algorithm combining the decoded master key with the MMS user device's phone number and the session ID.