s the RAND sequence and creates the RES, AUTN, CK' and IK' parameters from the key Ki and the RAND sequence. Wi-Fi Integration to the 4G Mobile Network 5) The HSS entity transmits the authentication vectors to the AAA server in the AIA (Authentication-Information-Answer) DIAMETER message. 6) The AAA server derives the two keys CK' and IK' to generate the master key PMK and generates a pseudonym and possibly an identifier for the rapid renewal of the authentication. The pseudonym and the identifier are temporary identities constructed from encryption of the private identity IMSI, using the advanced encryption standard (AES) algorithm. The same secret key is used by all AAA servers. The AAA server transmits to the trusted Wi-Fi access the EAP Request/EAP-Method AKA' Challenge message containing the identity of the access network, the RAND sequence, the AUTN seal, the pseudonym and possibly the identifier for the renewal of the authentication. This message is transmitted in a DEA DIAMETER message and contains a message authentication code (MAC) for the integrity check. 7) Trusted Wi-Fi access transfers the EAP Response/EAP-Method AKA' Challenge message to the mobile. 8) The mobile locally calculates, from its key Ki and the received RAND number, the key PMK, its seal RES and that of the AUTN network. The mobile compares the received AUTN with the calculated value. If both values are the same, the network is authenticated. The mobile also controls the integrity of the received message. The mobile transmits the EAP Response/EAP-Method AKA' Challenge message containing the RES seal and the MAC seal for the integrity check of the message to the trusted Wi-Fi access. 9) Trusted Wi-Fi access transfers the EAP Response/EAP-Method AKA' Challenge message to the AAA server in a DER DIAMETER message. 10) The AAA server checks the integrity of the received message and compares the RES seal received from the mobile to that received from the HSS entity. If the two values are identical, the mobile is authenticated. The AAA server 