Formal security model research based on Petri-net

Information security model is constructed by the method of decomposing security requirements from layer to layer and fractionalizing step by step through analyzing information security requirement in this paper. At the same time, object Petri net is introduced in the process of modeling information security system. Object Petri net can reduce problem state and control state number at the scale of accepting, then different level´s security requirements are satisfied. The model applying OPN can be deleted and added according to the security requirement, which is proved by the instance of security system that only has the requirement of confidentiality.