A Tutorial on the Interoperability of Self-sovereign Identities

TL;DR

This paper provides a comprehensive overview of self-sovereign identity interoperability, defining key concepts and presenting a reference model to facilitate understanding and implementation across diverse systems.

Contribution

It introduces a formal definition of self-sovereign identity interoperability and proposes a reference model outlining essential components and considerations for achieving interoperability.

Findings

Defined interoperability in the context of self-sovereign identities

Developed a reference model for implementation components

Clarified dependencies and trust mechanisms

Abstract

Self-sovereign identity is the latest digital identity paradigm that allows users, organizations, and things to manage identity in a decentralized fashion without any central authority controlling the process of issuing identities and verifying assertions. Following this paradigm, implementations have emerged in recent years, with some having different underlying technologies. These technological differences often create interoperability problems between software that interact with each other from different implementations. Although a common problem, there is no common understanding of self-sovereign identity interoperability. In the context of this tutorial, we create a definition of interoperability of self-sovereign identities to enable a common understanding. Moreover, due to the decentralized nature, interoperability of self-sovereign identities depends on multiple components, such as ones responsible for establishing trust or enabling secure communication between entities without centralized authorities. To understand those components and their dependencies, we also present a reference model that maps the required components and considerations that build up a self-sovereign identity implementation. The reference model helps address the question of how to achieve interoperability between different implementations.