Then security model PBSM-DDB (Policy-Based Security Model of Distributed Database) is brought forward to accurately describe DDB security demands with 9 formalized regulations.

• 接着提出安全模型PBSM-DDB(Policy-BasedSecurity Model of Distributed Database)，通过9条形式化安全规则对分布式数据库安全需求进行了全面描述；