随着LTE/SAE网络架构的改变,原来UMTS提供的网络接入安全机制已不能够满足网络变化的需求。为了应对所面临的各种威胁,LTE/SAE针对网络接入安全进行了大幅度的改进。文中主要针对LTE/SAE网络的安全层次、密钥架构和状态转换间的密钥管理机制等方面进行了研究,最后分析了存在的问题。 With the change of LTE / SAE network architecture, the original network access security mechanism provided by UMTS has not been able to meet the needs of network changes. In response to the various threats it faces, LTE / SAE has dramatically improved network access security. This paper mainly studies the security level of LTE / SAE network, the key architecture and the key management mechanism between state transitions, and finally analyzes the existing problems.