Patent ID: 8457308

Claim:
A communication system for protecting messages between two mobile phones, the communication system comprising: a first mobile phone and a second mobile phone, the first mobile phone comprising: a storage device that stores messages received by the first mobile phone; and at least one processor that executes a message decryption unit, the message decryption unit comprising: a setting module that sets a plurality of protective parameters in the storage device, the protective parameters comprising a message security level of a short message that identifies an importance of the short message; a calculation module that generates an encryption key and a decryption key according to the plurality of protective parameters, and stores the decryption key into the storage device; a registry module that registers the encryption key to the second mobile phone through a wireless network; and a decryption module that determines whether a short message received from the second mobile phone is an encrypted message according to an encryption tag of the short message, obtains the decryption key from the storage device according to the message security level of the short message if the short message is the encrypted message, decrypts the encrypted message to a readable message according to the decryption key, and displays the readable message on a display screen of the first mobile phone.