Abstract: According to the admission control requirements of multi-level classified network (MLCN)，a secure access model based on trusted network connection was proposed. I3y introducing security attribute checking rule, the security attribute of accessing device and its objects were checked in order to ensure that they would not lead to sensitive information leakage. By introducing integrity measurement rule, mutual measurement between the network and the device can be achieved. Based on the access security model, an access system framework for MLCN and an accompanying authentication protocol were put forward. hhe protocol performs integrity measurement before authenticating user authentication to achieve reliable mutual authentication. Comparative analysis indicates that the protocol is relatively more efficient.

Key words: Multi-level classified network,Trusted network connection, Access authentication, Security attribute