Sensitivity-based synchronisation protocol to prevent illegal information flow among objects

Abstract

In information systems, a transaction may illegally read data stored in an object, which the transaction is not allowed to read. A transaction illegally writes data to an object after issuing illegal read. The write-abortion (WA), read-write-abortion (RWA) and flexible RWA (FRWA) protocols to prevent illegal information flow are proposed in our previous papers. In the WA and RWA, a transaction is aborted once issuing an illegal write and illegal read, respectively. In the WA, some reads are meaninglessly performed. In the RWA, some reads are lost. In the FRWA, a transaction is aborted with some probability once issuing illegal read. We newly introduce an object sensitivity concept to decide on the abortion probability. In the evaluation, the execution time of each transaction in the FRWA with object sensitivity is shorter than the WA and more number of reads can be performed than the RWA.