A privacy protection model on internal networks

Information privacy protection is an essential problem in internal networks. The Bell-LaPadula Model (abbreviated BLP) is a state machine model used for enforcing access control, while it can't be used for networks. L-BLP model is designed for Local Area Networks(LAN) while it can't be proved security. We reveal the security problems in L-BLP and propose a security model based on BLP. We define five new state transition rules, which are designed for LAN with high usability. Our model can be proved to be secure in mathematics, and we implement a prototype system based from it. The experimental results show that our model can effectively prevent leakages of secrets.