基于关系数据库的极松散结构数据模型的访问控制研究

Access Control in Very Loosely Structured Data Model Using Relational Databases

本文提出一个针对数据空间环境下极松散结构模型的细粒度和动态的访问控制框架:首先定义通用的极松散结构模型GLSDM(General very Loosely-Structured Data Model);给出GLSDM到关系表的映射方法,将GLSDM上细粒度的访问控制转换为关系表的row、cell等安全级别的访问;通过动态查询重写,在用户执行查询时将GLSDM的权限信息添加到SQL语句中,从而实现GLSDM的动态访问控制.理论和实验证明该框架是可行和有效的,本文的映射方法和动态查询重写算法能够保证对GLSDM的访问控制通过等价的关系数据库的访问控制来实现.

This paper proposes a framework to efficiently support dynamic,fine-grained access control for the very loosely structured data model,named GLSDM（General very Loosely-Structured Data Model）,which is presented based on the current dataspace data models.In the framework,GLSDM is mapped into and stored in relational databases,and then the fine-grained access control in GLSDM is converted into the corresponding fine-grained security（e.g.,row-level and cell-level security） in relational databases.A query rewriting algorithm is also given to dynamically imbed GLSDM security information into SQL statements the user issues,thus,dynamic access control is realized during the period of query processing.Finally,the validity of the framework is proved by theory and experiment,that is,the GLSDMto-relational mapping method and query rewriting algorithm in this paper can ensure the access control in GLSDM is equivalent to that in relational databases.