Fog computing can effectively provide a variety of application support for the fast-growing number of Internet of Things devices. However, the unique characteristics of fog computing also bring new security problems, especially the identity authentication in fog computing will face new challenges: Low latency (cloud servers should not be involved in authentication); fog servers are not completely trusted; robustness (no user reregistration is required when a fog server leaves fog) and lightweight (fog devices have constrained resources). In order to solve these problems faced by identity authe...
