An Authenticated Key Exchange Protocol for Multi-Server Architecture in 5G Networks

Currently, the popularity of the Internet of Things (IoT) has brought about an increase in the amount of data, so multi-server distributed cloud computing has been widely used in various applications that have brought convenience to our daily lives. At the same time, the development of the fifth generation (5G) of mobile communication technology has gradually become the main driving force for the popularization of the IoT. Because the 5G network is a heterogeneous network with multiple servers and small cells, the mutual authentication protocol under multiple servers is also applicable to the 5G network environment. However, much of the data will have serious storage and security issues during transmission. Aiming at the security issues in a multi-server (M-S) architecture, in 2018, Wu et al. proposed an authentication protocol in a distributed cloud environment. They claimed that their protocol is secure and resistant to various known types of attacks. However, we found that their protocol does not guarantee perfect forward secrecy (PFS) and suffers from privileged insider (PI) attacks. Such attacks will cause data to be out of sync. Therefore, we improved Wu et al.'s protocol and proposed an improvement in the 5G network environment. Finally, we performed a security analysis on the proposed protocol, including the automatic encryption protocol tool ProVerif, BAN logic, and informal security analysis, which proved that our protocol is secure. Compared with similar existing schemes, we have proved the efficiency of the scheme and achieved higher security standards.