ChorSSI: A Model-Driven Framework for Self-Sovereign Identity Systems on Blockchain

The advent of the digital era has underscored the pivotal role of identity in online activities due to our increasing reliance on digital platforms. Consequently, various identity management systems have emerged, mainly relying on centralised infrastructures and exposed to security vulnerabilities. Self-Sovereign Identity (SSI) presents a promising alternative, as it allows individuals to manage their personal data autonomously and share it securely with others, eliminating the necessity for dependence on a central authority. In particular, the advent of blockchain technology has enabled the creation of novel SSI systems, thanks to its key characteristics of security, decentralisation and control over data. Nevertheless, the complexity and challenges associated with developing such systems and executing related operations pose significant barriers to the broader adoption of the SSI paradigm, particularly for users lacking expertise in the domain. To simplify the development and usability of SSI systems, in this work we propose ChorSSI, a model-driven BPMN-based framework that supports the modelling of an SSI system and the execution of the related interactions. The design relies on BPMN choreography diagrams, permitting the representation of SSI interactions between parties in a distributed manner. The proposed framework was implemented and the feasibility of the tool was assessed over the real Chromaway property transaction case study.