DAO attack showed that formal verification of smart contracts is an important issue that should be addressed to prevent irreversible consequences due to design faults activation in Blockchain applications. This paper proposes a modeling method of an Ethereum application based on smart contracts, with the aim of applying a formal method, namely Model-Checking, to verify that the application implementation complies with its specification, formalized by a set of temporal logic propositions. NuSMV tool has been chosen to support this first approach. The proposed model template is shaped by three layers capturing respectively the behavior of Ethereum blockchain, the smart contracts themselves and the execution framework. The approach is illustrated by a case study coming from energy market field.

This paper presents a modeling framework that permits to describe in an integrated manner the structure of the critical system to analyze, by using an enriched fault tree, the dysfunctional behavior of its components, by means of Markov processes, and the reconfiguration strategies that have been planned to ensure safety and availability, with Moore machines. This framework has been developed from BDMP (Boolean logic Driven Markov Processes), a previous framework for dynamic repairable systems. First, the contribution is motivated by pinpointing the limitations of BDMP to model complex reconfiguration strategies and the failures of the control of these strategies. The syntax and semantics of GBDMP (Generalized Boolean logic Driven Markov Processes) are then formally defined; in particular, an algorithm to analyze the dynamic behavior of a GBDMP model is developed. The modeling capabilities of this framework are illustrated on three representative examples. Last, qualitative and quantitative analysis of GDBMP models highlight the benefits of the approach.

This paper build the foundations of a simulation tool for blockchain-based applications. It takes advantage of the huge expressiveness and extensibility of PyCATSHOO framework to deal with the important variability of blockchain implementations and properties of interest. A simple stochastic model of generic blockchain-style distributed consensus system and associated performance indicators are proposed (performance in terms of consistency and ability to discard double-spending attacks). Monte Carlo simulations are applied to assess the indicators and determine their sensitivity to the variation of input parameters.

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This paper proposes an extension of the BDMP (Boolean logic Driven Markov Processes) formalism for enriching its capabilities to model replacement and resumption mechanisms in repairable systems. The implicit assumptions made by the classical BDMP to describe these mechanisms are first highlighted. An analogy between standby redundancies management in critical systems and preemption mechanisms in concurrent systems is then proposed. This permits to formally define an extension of BDMP that allows several replacement and resumption mechanisms be specified. A case study illustrates the benefits of this proposal.