upon receiving this message entity b decrypts it using the decrypted rana it verifies the hash of ranb concatenated with rana note at this step entity b has authenticated entity a and is assured that entity a knows ranb entity b sends the keyconfirmb message to entity a step 312 keyconfirmb consists of the hash of the decrypted portion of the keyconfirma message upon receiving this message entity a verifies the hash note at this step entity a has authenticated entity b and is assured that entity b knows rana at this point both entities have authenticated each other and have confirmed that they each share the same rana and ranb rana and ranb can now be used to derive a session encryption key sk and a mac key mk based on a key derivation function kdf for use with further communications between the parties step 314 the messages details are given below the helloa message is sent to initiate the mutual authentication with key confirmation protocol the hello a has a u201c version u201d parameter and a u201c rootandchains u201d parameter the version parameter may be an 8 bit value that contains the protocol version of this message it is mapped as the 5 msbs for the major version and the 3 lsbs for the minor version the rootandchains parameter may be an array of the root hashes and certificate chains for entity a under all the trust models supported by a the structure for the parameter roothashandcertchain is a parameter roothash which is the sha 1 hash of the trust model 39 s root public key and a parameter certchain the entity 39.