Abstract: Machine type communication (MTC),as the basis of the Internet of things,is a wide open area in market and a great application trend.The MTC networks can be strongly supported by the LTE-A networks,and the 3rd Generation Partnership Project (3GPP) has formally defined the MTC in the standard of Release 10.Compared to the normal mobile user equipment,the MTC devices have some special features,such as the huger quantity and lower power consumption.These features lead to more research challenges for the identity authentication in the LTE-A networks.When a mass of MTC devices are accessed to the LTE-A network simultaneously with a full authentication and key agreement process for each device,the communication signaling would congest the network.Meanwhile,the limited computation resources in MTC devices do not allow too many operations.Aimed at the congestion problems in the authentication processes,an authentication and key agreement protocol based on the aggregated proxy signature and message authentication code was proposed and named as EGAKA.The protocol adopts the aggregated proxy signature to make the LTE-A networks able to authenticate multiple MTC devices simultaneously and minimize the communication consumption.And the adoption of the message authentication code can decrease the computation consumption of the key agreement process.Then,the protocol was modeled and analyzed by the colored Petri nets (CPN),whose results demonstrate that the protocol is safe.Finally,via the performance analysis,the results demonstrate that the communication consumption is better than other protocols of the same kind,and the computation consumption is better than other protocols of the same kind which adopt the asymmetric encryption.

Key words: LTE-A,MTC,Group authentication,Key agreement,CPN