The simulation relation for formal E-Contracts

Abstract

Relationships between entities in today’s increasingly interconnected context have grown in complexity and evolved from simple communication processes to more complicated distributed systems. Electronics contracts (e-contracts) are of general purpose and aimed to specify relationships in a wide variety of scenario, including web and cloud services, inter and intra organization, electronic banking, etc. It is in this context that we aim to develop a consistent definition for these relationships together with a set of techniques to check their proper use. In this paper we present a process algebra to describe these contract relationships and a set of formal machinery to determine whether an implementation follows the rules established by these contracts. The main formal technique used is a simulation relation where an implementation is checked step by step against a given contract. Several toy examples are provided to facilitate understanding of the formal definitions.