Designing Multilevel Relational Databases for Security-Control

一个设计良好的数据库必须平衡安全控制和操作效率。因此，主要目标是发展一种在动态环境中统一安全（访问控制和推理控制）和效率方面的多级数据库设计理论。本项目确定了这些方面所施加的关键约束，并为数据库设计制定了实用的指导方针。重点放在数据依赖基础的推理控制和异常消除。采用的方法处理格理论关系模型，通过在用户视图中抽象或模糊敏感信息来增强数据库安全性。该模型使用由自然等价构建的“上下文”。上下文产生能够容纳抽象的多层关系，并支持丰富和高度安全的数据语言。上下文也在抽象中包含语义；这有助于平衡用户便利性和数据库安全性。格理论框架简化了研究；经典的设计问题也很容易映射到它们的多层公式。调查还集中在安全控制模型的Oracle实现上。特别考虑了查询处理功能的实现。本研究的结果将对处理抽象信息的数据库的设计产生重大影响，特别是那些支持人工智能和专家系统应用程序的数据库，因为健壮和有效的安全控制是数据库和知识库设计者面临的关键问题。//

A well-designed database must balance security-control and operational efficiency. Consequently, the principal objective is to develop a design theory for multilevel databases unifying security (access-control and inference-control) and efficiency aspects in a dynamic environment. This project identifies the key constraints imposed by these aspects and formulates practical guidelines for database design. Emphasis is placed on data dependencies fundamental to inference-control and anomaly- elimination. The approach employed deals with a lattice-theoretic relational model enforcing database security by abstracting or clouding sensitive information in user views. The model uses "contexts" constructed from natural equivalences. Contexts induce multilevel relations capable of holding abstraction, and support a rich and highly secure data language. Contexts also incorporate semantics in abstraction; this helps balance user convenience and database security. The lattice-theoretic framework simplifies the investigation; classical design issues are also readily mapped to their multilevel formulations. The investigation also focuses on an Oracle implementation of the security-control model. Special consideration is given to implementing the query-handling facility. The results of this research will have a significant impact on the design of databases handling abstract information, and particularly those supporting AI and expert systems applications, as robust and efficient security-control is a critical issue facing database and knowledge-base designers. //