In the third handshaking step, the master node simply sends a confirmation message to the slave node, which is encrypted with the symmetric cryptographic algorithm SCA and the key SC_Key.
By now, the master node and the slave node have been authenticated by each other. A cryptographic algorithm SCA with the corresponding key SC_Key, that will be used to encrypt all the data transmissions in further communications, has been determined by both the master node and the slave node. A third party of the communication is also excluded. A secure connection between the master node and the slave node is established. The work in this phase is done.