支持多策略的安全数据库系统体系结构

提出了在DBMS中支持多种安全策略的需求,指出了在DBMS中支持多安全策略所面临的主要问题,针对这些问题提出了支持多安全策略的DBMS体系结构(MSDA).在抽象层次上该体系结构与GFAC一致,主要区别表现在性能优化和面向DBMS的适应性改造.为了提高系统性能,MSDA在客体管理器中引入了访问判定缓存.而为了适用于DBMS,MSDA在体系结构层次引入了重写来支持高效的细粒度访问控制.此外还引入了访问上下文栈来支持视图和存储过程这类的受控访问机制.给出了MSDA在LOIS SDBMS v3.0中的实现,并通过实验给出了MSDA对目标系统的性能影响分析.结果表明,MSDA将访问控制判定与实施分离,既能充分解决数据库系统中支持多安全策略的相关问题,同时能够与当前主流关系数据库系统相匹配,不会造成目标系统性能的显著下降.

Multi-policy secure database system architecture

The requirements of supporting multiple security policies in DBMS and the problems to be solved in order to do so are prescnted.A multi-policy secure database system architecture(MSDA) according to these problems is provided.In an abstract level,MSDA conforms to GFAC,however,MSDA is designed in such a manner that it leads to better performance and is more suitable for DBMS.In order to improve system performance,MSDA introduces access decision cache.And to make the architecture more fit for DBMS,MSDA presents rewrite component to support fine-grained access control.In addition,MSDA adopts access context stack to support controlled access mechanisms such as views and stored procedures.This paper describes the implementation of MSDA in LOIS SDBMS v3.0 and analyzes the performance penalty brought about by MSDA.As the result,MSDA separates access control decision and enforcement,solves the problems of supporting multiple policies in DBMS,fits well with main streams database systems,and will not influence the performance of target system to much.