Availability Analysis Method of Multilevel Security Models with Credibility Characteristics

A multilevel security (MLS) model with credibility characteristics, the credibility-based Bell-LaPadula (CBLP) security model, has been proposed to resolve the problem of trusted subjectspsila hidden security flaw and poor system usability in present MLS systems in the previous paper of the authors. A sampling statistics method is proposed in this paper to evaluate the availability of the CBLP model by obtaining the variation curve of the subjectspsila credibility and the rejection ratio of access operations. The validity of this method was achieved according to the strong law of large numbers and the central limit theorem. The sampling statistics results of the CBLP model in specific scenarios showed that it is highly consistent with that of the formal analysis method and has lower computational complexity.