healthcare Article Health-ID: A Blockchain-Based Decentralized Identity Management for Remote Healthcare Ibrahim Tariq Javed 1, * , Fares Alharbi 2 , Badr Bellaj 3 , Tiziana Margaria 1,4 , Noel Crespi 3 and Kashif Naseer Qureshi 5   Citation: Javed, I.T.; Alharbi, F.; Bellaj, B.; Margaria, T.; Crespi, N.; Qureshi, K.N. Health-ID: A Blockchain-Based Decentralized Identity Management for Remote Healthcare. Healthcare 2021, 9, 712. https://doi.org/10.3390/ healthcare9060712 Academic Editor:Daniele Giansanti Received: 24 April 2021 Accepted: 5 June 2021 Published: 10 June 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Lero-Science Foundation Ireland Research Centre for Software, University of Limerick, V94 T9PX Limerick, Ireland; tiziana.margaria@ul.ie 2 Computer Science Department, Shaqra University, Shaqra 15526, Saudi Arabia; faalhrbi@su.edu.sa 3 Institut Mines-Télécom, Télécom SudParis, CEDEX, 91011 Evry, France; badr.bellaj@telecom-sudparis.eu (B.B.); noel.crespi@mines-telecom.fr (N.C.) 4 The Health Research Institute (HRI), University of Limerick, V94 T9PX Limerick, Ireland 5 Department of Computer Science, Bahria University, Islamabad 44000, Pakistan; knaseer.buic@bahria.edu.pk * Correspondence: Ibrahimtariq.javed@lero.ie Abstract: COVID-19 has made eHealth an imperative. The pandemic has been a true catalyst for remote eHealth solutions such as teleHealth. Telehealth facilitates care, diagnoses, and treatment remotely, making them more efficient, accessible, and economical. However, they have a centralized identity management system that restricts the interoperability of patient and healthcare provider identification. Thus, creating silos of users that are unable to authenticate themselves beyond their eHealth application’s domain. Furthermore, the consumers of remote eHealth applications are forced to trust their service providers completely. They cannot check whether their eHealth service providers adhere to the regulations to ensure the security and privacy of their identity information. Therefore, we present a blockchain-based decentralized identity management system that allows patients and healthcare providers to identify and authenticate themselves transparently and securely across different eHealth domains. Patients and healthcare providers are uniquely identified by their health identifiers (healthIDs). The identity attributes are attested by a healthcare regulator, indexed on the blockchain, and stored by the identity owner. We implemented smart contracts on an Ethereum consortium blockchain to facilities identification and authentication procedures. We further analyze the performance using different metrics, including transaction gas cost, transaction per second, number of blocks lost, and block propagation time. Parameters including block-time, gas-limit, and sealers are adjusted to achieve the optimal performance of our consortium blockchain. Keywords: digital identity; decentralized identity; identity management; healthcare; blockchain; smart contract; Ethereum 1. Introduction Since SARS-CoV-2 (COVID-19) emerged, the demand for eHealth has gone viral. The novel coronavirus has swept across communities forcing a new normal that requires social distancing. Governments strongly suggest enforcing medical distancing to minimize physical contact between patients and healthcare providers. As a result, hospitals and other healthcare organizations have rapidly adopted digital alternatives to deliver healthcare services. Telehealth applications facilitate clinical benefits for patients such as consultation, diagnoses, treatment, and prevention from a distance overcoming the geographical barrier. They can also support non-clinical services for healthcare providers, such as training, meetings, and education [1]. Furthermore, eHealth applications also provide real-time health monitoring using various devices and sensors [2]. In 2020, remote healthcare applications shifted from a previously slow adoption rate to a record pace of uptake. The searches for online consultations have sky rocked by 350%. Whereas in 2021, the global Healthcare 2021, 9, 712. https://doi.org/10.3390/healthcare9060712 https://www.mdpi.com/journal/healthcare