Ensuring atomicity of multilevel transactions
Paul Ammann, Sushil Jajodia, Indrakshi Ray · 1996
Ensuring atomicity is a major outstanding problem with present methods of handling multilevel transactions. The chief difficulty is that a high section of a transaction may be unable to complete due to violations of the integrity constraints, and a rollback of sections can be exploited to implement a covert channel. We define a notion of semantic atomicity which guarantees that either all or none of the sections of a transaction are present in any history. The notion of correct executions in our model is based on semantic correctness -- that is, maintenance of integrity constraints -- rather than serializability. We give a method whereby the applicationdeveloper can statically analyze the set of transactions in the application and determine if the set ensures semantic atomicity and other desirable properties. 1. Introduction Most of the research of transaction processing in multilevel secure databases is limited to single-level transactions. A fixed security level is associated with a...