While the secure transaction schedulers in multilevel secure database systems synchronize transactions cleared at different security levels, they must consider the problem of covert channel. Through the covert channel, malicious users leak secret information in a way of intentional interference among the transactions that they invoked. Much work had been done for closing the covert channel. Although they succeeded in closing the covert channel, they unfortunately failed in preserving correctness, sufficient recentness of versions read, or fairness with respect to availability. In this paper, we present a new secure transaction scheduler, named Verified Order-based Transaction Scheduler (VO) that founds on multiversion database. VO overcomes the problems of previous work.
International Conference on Database and Expert Systems Applications, pp.254 - 263