摘要
In this paper the authors show how software component design can affect security properties through different composition operators. The authors define software composition as the result of aggregating and/or associating a component to a software system. The component itself may be informational or functional and carry a certain level of security attribute. The authors first show that the security attributes or properties form a lattice structure when combined with the appropriate least upper bound and greatest lower bound type of operators. Three composition operators, named C l, C2 and C3 are developed. The system＇s security properties resulting from these compositions are then studied. The authors discuss how different composition operators maintain, relax and restrict the security properties. Finally, the authors show that C1 and C2 composition operators are order-sensitive and that C3 is order-insensitive.
