A Blockchain-Based Federated Identity Framework for Secure Multi-Domain IoT Interoperability

The proliferation of Internet of Things (IoT) deployments within various administrative and technological spheres of life metadata a demand for secure, scalable, and interoperableidentity authentication. Current identity systems on blockchain are mostly dedicated to a specific domain and do not support direct cross-chain identity federation. In this work, we present a blockchain layer for the federated identity model to provide secure and privacy-preserving authentication across different IoT domains. The research contribution of this work is the proposal and investigation of a decentralized IDM solution using Merkleproof, smart contract, and quorum-based validator consensus to realize pseudonymous IDM registration, cross-domain assertion, and life-cycle management without depending on centralized brokers. Identity registration on native blockchain, cryptographically commitment generation, and cross-chain attestation via programmable smart contract and validator attestation are the three steps of this approach. In experiments on Ethereum-compatibletestnets, the proposed scheme realizes efficient identity assertions with an average latency of 4.1 s, communication payloads less than 1.6 KB, and throughput over 520 assertions per min. This technique maintains security against impersonation, Sybil, replay, and collusion attacks while maintaining pseudonymity and onchain audibility. The presented model is applicable to real-time and large-scale IoT using security cross-chain identity interoperability.