A security BLP model used in classified protection system

With rapid development of the Web system, security is becoming a most important part of computer science and technology. Security model introduced for Web resource as precise design guidance, which works during the entire design, coding, review process, evaluation and accreditation processes. There are several security models which focus on different aspects of security. This paper´s intent is to introduce the most classical multilevel computer security model - Bell-LaPadula model(BLP) and some improvements that have been done well.