Wireless body area network security access method

The invention discloses a wireless body area network security access method. Two interaction modes, namely, the unicast mode and the multicast mode, are set; two launching modes are set, and in other words, a network coordinator launches hand shaking and sensor nodes launch hand shaking; thus, when a certain part is injured and the blood pressure suddenly rises or in other words, the measurement indexes of a certain or some sensor nodes exceed the corresponding index limitations, the corresponding sensor nodes actively launch the hand shaking process, the situations of patients are rapidly fed back to medical staff, and patients are helped in time. According to the method, dynamic negotiation of a user conversation key is achieved through enhanced four-step hand shaking, hand shaking information is reduced, all the information is encrypted, the unicast access mode and the multicast access mode are set, and the remote access problem is solved through a multi-hop method. The method has the advantages that the access efficiency of a large number of sensing nodes is high, security is high, and the energy consumption is low, and the method can be used for the access of the sensing nodes in a wireless body area network and the dynamic negotiation of the user conversation key.