Key points are not available for this paper at this time.
The paper discusses the nature of systems for protection of information in the central memory of a computer, describing the potentialities and limitations of a variety of approaches. It is based upon work done in the course of a current project on protection systems at the Computer Laboratory, Cambridge, and outlines a system which is being developed to the point of hardware implementation in the Laboratory.
Roger M. Needham (Sat,) studied this question.