Elesto Protocol: Self-Sovereign Identity System

The key to the emerging digital society and economy is digital identity, a fundamental component of digital transformation in representing any real-world entity in digital form. An effective digital identity is essential to secure a successful digital future, especially as the demand for digital services grows.Since the genesis of digital identification, numerous identity management (IdM) systems have been developed and enforced to address the increasing need to manage identities based on the needs of individuals and organizations. This advancement of IdM systems offers an incremental process that leads the user to gain control of identity ownership and personal data while raising identity management concerns such as sovereignty, storage, access control, security, privacy, and safeguarding. Self-sovereign identity (SSI), recently recognized as a promising IdM, can provide sovereignty to the identity owner while addressing these concerns.The Elesto protocol is an emerging open-source, public permissionless blockchain-based implementation that uses SSI for identity management for users, organizations, and other entities. The protocol leverages W3C specifications for decentralized identifiers (DID), verifiable credentials (VC), DIDComm messaging specifications, and SSI agents.The Elesto protocol is an application-specific blockchain implementation using the Cosmos SDK framework, Tendermint Proof-of-Stake (PoS) consensus, the Inter-Blockchain Communication protocol (IBC), and design satisfies all of the fundamental requirements and principles of SSI.This paper presents the design and implementation of the Elesto protocol as an identity infrastructure. Three use cases illustrate how the protocol helps overcome the highlighted problems by decentralizing or extending functionalities in the blockchain infrastructure.