A FLEXIBLE READ-WRITE ABORTION PROTOCOL TO PREVENT ILLEGAL INFORMATION FLOW AMONG OBJECTS
Shigenari Nakamura, Dilawaer Duolikun, Tomoya Enokido, Makoto Takizawa · Journal of Multimedia · 2015
In information systems, types of objects like multimedia objects are manipulated in var- ious applications like mobile systems. Here, information in objects may ow to another object. Suppose a transaction reads data in an object o1 and then writes data to another object o2. If a transaction reads the data in the object o2, the transaction can read data in the object o1 even if the transaction is not granted a read access right on the object o1. Here, the transaction illegally reads data in the object o2. Here, information in the object o1 might illegally ow to the object o2. A transaction illegally writes data to an object after illegally reading data in some object. In addition, we consider a suspicious object whose data is not allowed to ow to another object. A transaction suspiciously reads data in a suspicious object. A transaction impossibly writes data to an object after reading the data in a suspicious object. Write-abortion (WA) and read-write-abortion (RWA) protocols to prevent illegal information ow are already proposed in our pre- vious studies. In the WA protocol, a transaction is aborted once issuing an illegal or impossible write operation to an object. Read operations are meaninglessly performed since the read operations are undone due to the abortion of the transaction. In the RWA protocol, a transaction is aborted once issuing an illegal read or impossible write opera- tion to an object. Here, read operations to be performed after an illegal read operations are lost since a transaction is aborted just on issuing an illegal read operation. In this paper, we newly propose a exible read-write abortion (FRWA) protocol to reduce the number of meaningless and lost read operations. Here, a transaction is aborted with some probability if the transaction illegally reads data in an object. We evaluate the FRWA protocols compared with the WA and RWA protocols. We show the execution time of each transaction in the FRWA protocols is shorter than the WA protocols and more number of read operations can be performed in the RWA protocols.