An adjustment method for secure label of subject based on trust evaluation

Because secure label is static in BLP model, secure label of subject is unalterable in multi-level network which is vulnerable to suffer the risk of access. This paper analyzed the character of subject in multi-level network and put forward an adjustment method for secure label of subject based on trust evaluation. The method collects evidences of access history of subject from audit systems in the same secure domain, and then evaluates trust degree about confidentiality, integrality and availability by evidences and forms current trust section of subject on onfidentiality, integrality and availability, finally secure label is adjusted by trust section for reducing risk of information system.