Protected object references in heterogeneous distributed systems

In object-oriented distributed processing systems, all interactions between objects occur solely through their defined external interfaces. The authors argue that object reference parameters should be supported in such systems for reasons of programming style and productivity. It is not sufficient to pass the name of an object as a string. The system must be aware of reference parameters and provide means to control and protect the delegation of access. The authors´ emphasis is on motivating the need for protected object references and on showing that their efficient implementation is feasible in diverse environments. The design is guided by the principle of minimal trust. Two prototype implementations of object reference support systems are presented. One is an example in which, right from the start, object references are integrated into the design of a kernel for a network operating system for heterogeneous distributed environments. The other prototype shows how object references can be added to a popular remote procedure call package in an upwardly compatible way