Converting BPMN Diagrams to Privacy Calculus

TL;DR

This paper introduces a method to convert BPMN business process diagrams into Privacy Calculus terms, facilitating the development of privacy-preserving software by bridging graphical process models and formal privacy frameworks.

Contribution

It provides a formal mathematical conversion from BPMN diagrams to Privacy Calculus, including an implemented software tool, enabling integration of business process modeling with privacy analysis.

Findings

Conversion method successfully implemented as a software tool

Enables formal privacy analysis of BPMN diagrams

Facilitates development of privacy-preserving software workflows

Abstract

The ecosystem of Privacy Calculus is a formal framework for privacy comprising (a) the Privacy Calculus, a Turing-complete language of message-exchanging processes based on the pi-calculus, (b) a privacy policy language, and (c) a type checker that checks adherence of Privacy Calculus terms to privacy policies. BPMN is a standard for the graphical description of business processes which aims to be understandable by all business users, from those with no technical background to those implementing software. This paper presents how (a subset of) BPMN diagrams can be converted to Privacy Calculus terms, in the hope that it will serve as a small piece of larger workflows for building privacy-preserving software. The conversion is described mathematically in the paper, but has also been implemented as a software tool.