Composed message authentication code

Front transmission, and is division multiple transmission device. The network transmission unit sub-news authentication code. The transmission units-based sub-news authentication code, obtaining the information collection message authentication code. , Then transmits multiple transmission unit and off message authentication code. The transmission device according message receiving and receiving information corresponding. The receiver and computer to the background message authentication code of the transmission device. The receiver multiple transmission units-based the background message authentication code, synthesis message authentication code end of the computer to the local. Synthesis message authentication code to compare with a comprehensive message authentication code for receiving the local, an information integrity and/or authenticity of determining to receiving.