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Enhancing database integrity and security through feedback to designers
Abstract
A Database Management System (DBMS) provides two guarantees of protection against misuse: integrity and security. However, in practice, the database designer finds these guarantees to be limited in scope. This dissertation shows how mechanical feedback can be provided to a database designer so that the limitations are mitigated. Further, we argue that such feedback is imperative for a specification based approach to database design. The first limiting factor is that integrity checking generally consumes excessive computing resources. Verifying the constraints at the end of every transaction is wasteful, especially considering abortions. The second limiting factor is the possible conflict between integrity and security. It arises from a malicious user who, with the knowledge of the integrity constraints, the preconditions of the transaction, and the input, may be able to learn secrets through cunning application of transactions. This dissertation extends the ADABTPL approach by examining transactions that do not preserve integrity; we demonstrate with a prototype how the designer can be provided with different kinds of feedback: they include run-time tests that are only sufficient for integrity preservation, updates which, when added to the transactions, restore integrity, as well as system-computed postconditions that are helpful in illustrating errors. The success of our approach depends on the rewrite rules the theorem prover is given; hence, we establish criteria for these rules to be complete and effective regarding various modes of feedback. Since the semantics provided by integrity constraints conflict with security, we introduce a formal means of specifying secrets and show that feedback can include the detection of the revelatory power of transactions.
Subject Area
Computer science
Recommended Citation
Mazumdar, Subhasish, "Enhancing database integrity and security through feedback to designers" (1991). Doctoral Dissertations Available from Proquest. AAI9207435.
https://scholarworks.umass.edu/dissertations/AAI9207435