As more and more Internet of Thing (IoT) devices are connected to satellite networks, the Zero-Trust Architecture brings dynamic security to the satellite-ground system, while frequent authentication creates challenges for system availability. To make the system's accommodate more IoT devices, this paper proposes a high-scalable authentication model (Hi-SAM). Hi-SAM introduces the Proof-of-Work idea to authentication, which allows device to obtain the network resource based on frequency. To optimize the frequency, mean field game is used for competition among devices, which can reduce the decision space of large-scale population games. And a dynamic time-range message authentication code is designed for security. From the test at large population scales, Hi-SAM is superior in the optimization of authentication workload and the anomaly detection efficiency.
