Design And Analysis Of Secure Scheduler For MLS Distributed Database Systems

Multilevel security requirements introduce a new dimension to traditional database schedulers as they cause covert channels. To prevent covert channels, scheduler for multilevel secure database should ensure that transactions at low security level are never delayed by high security level transactions in the event of a data conflict. This may subjected to an indefinite delay if it is forced to abort repeatedly to high security level transactions and making the secure scheduler unfair towards high security level transactions. This paper proposes secure database scheduler that is based on both optimistic and locking techniques (SO2PL) for multilevel secure distributed database systems. The proposed database scheduler is free from covert channels without starving the high security level transactions. Through a simulation study we evaluate the performance of the SO2PL and compare it with S2PL scheduler.