The Research of Multilevel Secure Concurrency Control Algorithm Base on Snapshots

In order to solve the transaction processing in multilevel security database,The multilevel secure concurrency control algorithm base on snapshots are presented.The algorithm requires two snapshots of the database at all but the system highest security level.High-level transactions access snapshots of low-level data instead of accessing low-level data directly.Snapshots can prevent starvation of high-level transactions without introducing covert channels.The basic concepts of snapshots are explained and the concurrency control algorithm based snapshots is given.At last the multilevel transactions execution histories resulting from the algorithm were proved to be serializable.