Biblio
This paper investigates mechanisms that guarantee secure information flow in a computer system. These mechanisms are examined within a mathematical framework suitable for formulating the requirements of secure information flow among security classes. The central component of the model is a lattice structure derived from the security classes and justified by the semantics of information flow. The lattice properties permit concise formulations of the security requirements of different existing systems and facilitate the construction of mechanisms that enforce security. The model provides a unifying view of all systems that restrict information flow, enables a classification of them according to security objectives, and suggests some new approaches. It also leads to the construction of automatic program certification mechanisms for verifying the secure flow of information through a program.
This article was identified by the SoS Best Scientific Cybersecurity Paper Competition Distinguished Experts as a Science of Security Significant Paper.
The Science of Security Paper Competition was developed to recognize and honor recently published papers that advance the science of cybersecurity. During the development of the competition, members of the Distinguished Experts group suggested that listing papers that made outstanding contributions, empirical or theoretical, to the science of cybersecurity in earlier years would also benefit the research community.
A model of protection mechanisms in computing systems is presented and its appropriateness is argued. The “safety” problem for protection systems under this model is to determine in a given situation whether a subject can acquire a particular right to an object. In restricted cases, it can be shown that this problem is decidable, i.e. there is an algorithm to determine whether a system in a particular configuration is safe. In general, and under surprisingly weak assumptions, it cannot be decided if a situation is safe. Various implications of this fact are discussed.
This article was identified by the SoS Best Scientific Cybersecurity Paper Competition Distinguished Experts as a Science of Security Significant Paper.
The Science of Security Paper Competition was developed to recognize and honor recently published papers that advance the science of cybersecurity. During the development of the competition, members of the Distinguished Experts group suggested that listing papers that made outstanding contributions, empirical or theoretical, to the science of cybersecurity in earlier years would also benefit the research community.
Abstract models are given which reflect the properties of most existing mechanisms for enforcing protection or access control, together with some possible implementations. The properties of existing systems are explicated in terms of the model and implementations.
This article was identified by the SoS Best Scientific Cybersecurity Paper Competition Distinguished Experts as a Science of Security Significant Paper. The Science of Security Paper Competition was developed to recognize and honor recently published papers that advance the science of cybersecurity. During the development of the competition, members of the Distinguished Experts group suggested that listing papers that made outstanding contributions, empirical or theoretical, to the science of cybersecurity in earlier years would also benefit the research community.
A brief review is given of the memory properties of non-linear ferroelectric materials in terms of the direction of polarization. A sensitive pulse method has been developed for obtaining static remanent polarization data of ferroelectric materials. This method has been applied to study the effect of pulse duration and amplitude and decay of polarization on ferroelectric ceramic materials with fairly high crystalline orientation. These studies indicate that ferroelectric memory devices can be operated in the megacycle ranges. Attempts have been made to develop electrostatically induced memory devices using ferroelectric substances as a medium for storing information. As an illustration, a ferroelectric memory using a new type of switching matrix is presented having a selection ratio 50 or more.