Verification of a Model of the Isolated Program Environment of Subjects Using the Lamport's Temporal Logic of Actions

Abstract

The article considers a modern approach to the creation of formal computer system security models, which consists in describing a model in some formal language suitable for its verification for compliance with the expected properties. The article provides an example of such a description in the form of a specification of a formal model of the isolated program environment in the language of the Lamport's temporal logic of actions. The specification is formed as an initial state of the system, a list of possible further actions and a set of invariants and temporal properties to which the system's states must correspond. The initial state is described by some entities that must exist in each system implementation. The system's actions are given in the form of predicates of pre- and postconditions, with some model's variables changing in the latter. Invariants and temporal properties are described in the form of predicates, whose truth must be checked in each possible state of the system or depending on the conditions occurring in previous or future states. The article considers the features of forming a security model specification in TLA+ notation and verifying it using special tools. In its conclusion, the article describes the results of verifying the specification of the formal model of the isolated program environment of subjects, the existing problems and directions for further research on this topic.