Process Algebraic Approach for Probabilistic Verification of Safety and Security Requirements of Smart IoT (Internet of Things) Systems in Digital Twin

Abstract

Process algebra can be considered one of the most practical formal methods for modeling Smart IoT Systems in Digital Twin, since each IoT device in the systems can be considered as a process. Further, some of the algebras are applied to predict the behavior of the systems. For example, PALOMA (Process Algebra for Located Markovian Agents) and PACSR (Probabilistic Algebra of Communicating Shared Resources) process algebras are designed to predict the behavior of IoT Systems with probability on choice operations. However, there is a lack of analytical methods in the algebras to predict the nondeterministic behavior of the systems. Further, there is no control mechanism to handle undesirable nondeterministic behavior of the systems. In order to overcome these limitations, this paper proposes a new process algebra, called dTP-Calculus, which can be used (1) to specify the nondeterministic behavior of the systems with static probability, (2) verify the safety and security requirements of the nondeterministic behavior with probability requirements, and (3) control undesirable nondeterministic behavior with dynamic probability. To demonstrate the feasibility and practicality of the approach, the SAVE (Specification, Analysis, Verification, Evaluation) tool has been developed on the ADOxx Meta-Modeling Platform and applied to a SEMS (Smart Emergency Medical Service) example. In addition, a miniature digital twin system for the SEMS example was constructed and applied to the SAVE tool as a proof of concept for Digital Twin. It shows that the approach with dTP-Calculus on the tool can be very efficient and effective for Smart IoT Systems in Digital Twin.

A Process Algebraic Approach to Predict and Control Uncertainty in Smart IoT Systems for Smart Cities Based on Permissible Probabilistic Equivalence

“…• The communication and movements of IoT devices can be represented by τ and δ actions in algebra, respectively [11]; • The decision and risk can be presented by nondeterministic choice operations with probability in algebra, respectively [11].…”

“…In addition, as a result of the verification, in case of the probabilistic requirements not being satisfied, it was shown, as a feasibility ground, that the probabilities making the decisions were enhanced at some arbitrarily high level so that the requirements were to be satisfied. The detailed steps of the approach in the previous research are as follows [11]; note that each step is indicated with the numbers from the figure:…”

“…In order to prove the feasibility of the approach in the paper, we developed a visual tool suite called SAVE (Specification, Analysis, Verification, Evaluation), and applied the approach to a smart EMS (emergency medical service) system [11,12].…”

“…One of the most suitable applications for dTP-Calculus can be smart IoT systems to represent the interactions and movements of the IoT with respect to mobility, temporality, and probability [11].…”

“…It is designed originally to specify, analyze, verify and evaluate Distributed Mobile Real-Time Systems (DM-RTSs) with dTP-Calculus, consisting of a modeler, simulator, analyzer, verifier, etc., as shown in Figure 6. Currently SAVE has been applied to the area of smart IoT systems for smart cities [11,12].…”