Electronic Health Record Storage using Blockchain

Amitoj Singh Chouhan Abhishek Rai

MT2017019 MT2017004
amitojsingh.chouhan@iiitb.org abhishek.rai@iiitb.org

May 1, 2018

Contents
1 Motivation 1

2 Objectives 1

3 Technical Explanation 2
3.1 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.2 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.3 Transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.4 Data Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

4 Technologies 5
4.1 Hyperledger Fabric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2 Hyperledger Composer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.3 JavaScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.4 node.js . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.5 npm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.6 HTML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.7 jQuery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Learning 7
5.1 Learning sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.2 Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6 Installation 8
6.1 Pre-requisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.2 Development Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.3 Deploying a Hyperledger Composer blockchain business network to Hy-
perledger Fabric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7 Future work 10
1 Motivation
In today’s world, users expect an instantaneous and seamless flow of data. Many indus-
tries have adopted or are beginning to adopt necessary technologies to guarantee their
users’ expectation for instant information. Unfortunately, the healthcare industry has
lagged behind. Legacy systems are burdensome, slow, oftentimes vulnerable and have
little role for the patient.

Health data contained in legacy systems is siloed and difficult to share with others
because of varying formats and standards. In short, the current healthcare data land-
scape is fragmented and ill-suited to the instantaneous needs of modern users.

The relationship between healthcare professionals and patients has long been a pa-
ternalistic one. In recent times however, there has been a significant shift of authority.
Medicine is being democratised and patients are more empowered.

At present, electronic health records (EHR) are stored on centralized databases in

which medical data remains largely non-portable. Centralization increases the security
risk footprint and requires trust in a single authority. Moreover, centralized databases
cannot ensure security and data integrity, regardless of de-identification and controlled
access requirements. Centralized health databases are legally a requirement and neces-
sity in most countries worldwide and therefore require an added layer of technology to
improve their portability and security.

2 Objectives
• Secure, immutable and decentralized EHR database with patient owing her/his
own health data

• Single version of the truth verified by the consensus of the participating hospitals

• On the tunes of upcoming digital health data bill DISHA in India

• Easy to share selective or all EHRs as consented by the patient

• Full medical history of a patient at one single point

• Easy verification of medical prescription

• Redacted EHRs for research purposes.

• Increased transparency

• No insurance fraud

1
3 Technical Explanation
3.1 Architecture
Application considers three types of users: Doctors, Patients and Researchers. Any one
of these users interacts with our main application user interface. Next, user will invoke
some query. SDK will verify global state of the blockchain and query will be submitted
to the blockchain through restful service-based API. Blockchain will send the request to
other peers for consensus. After the successful consensus, transaction will be submitted
to the blockchain and the subsequent key-value pair will be created or modified accord-
ing to the request.

3.2 Security
With creation of a new user, a 128-bit token is generated, and this token is stored in the
database on the backend. Then, whenever a user logs in the application its credentials
are verified, and its corresponding token is fetched from the backend via REST API.
Now with every query, application passes the user’s token and, on the backend REST
API verifies the token and gets to know the identity of the person. This is the first layer
of security.

Then when actual data is being pulled from the blockchain, blockchain verifies the
user identity with the certificate it issued when the user was created on the blockchain.
This forms second layer of security.

2
3.3 Transactions
Any interactions with health records are recorded as transactions on the network. Trans-
actions are viewable only to the participants associated with the transaction. Here are
examples of how transactions take place in the application.

Patient Granting Write Access

• Patient A grants write access to medical record to Doctor A

• Doctor A’s ID is added to Patient A’s authorized asset on the ledger

Patient Granting Read Access

• Patient A grants read access to medical record to Doctor A

• Doctor A’s ID is added to medical record’s authorized asset on the ledger

Doctor Referring Patient

• Doctor A updates the permissions to allow Doctor B to read the Patient’s medical
record

• Chaincode will check that Doctor A has permission to write on the medical record

• Doctor B’s ID is added to medical record’s authorized asset

• Patient A has to add Doctor B explicitly to his authorized list for write permission

3.4 Data Structure

Variable Type Variable Description

String Record ID A unique record ID
String Doctor ID Reference to a doctor
String Patient ID Reference to a patient
String Encounter ID Pointer to the encounter
containing description and
prescription
String Location Hospital where medical
record is generated
String Array Authorized List of read permitted doc-
tors
Date Time Encounter Time Time of the event

Table 1: Medical record

3
Variable Type Variable Description
String Encounter ID A unique encounter ID
mapped to a unique record
ID
String Description Description of the diagno-
sis
String Prescription Medical prescription

Table 2: Encounter

Variable Type Variable Description

String Patient ID A unique patient ID
String Array Authorized List of write permitted
doctors
String Patient Profile Reference to the patient
profile ID containing de-
mographic data

Table 3: Patient

Variable Type Variable Description

String Doctor ID A unique doctor ID
String Doctor Profile Reference to the doctor
profile ID containing de-
mographic data

Table 4: Doctor

4
 Variable Type Variable Description
String Profile ID A unique profile ID
String Patient ID Reference to a patient
String First Name First name of the patient
String Last Name Last name of the patient
String Email Address Email address of the pa-
tient
String Address Address of the patient
Date Time Date of birth To calculate age of the pa-
tient

Table 5: Patient profile

Variable Type Variable Description

String Profile ID A unique profile ID
String Doctor ID Reference to a doctor
String First Name First name of the doctor
String Last Name Last name of the doctor
String Email Address Email address of the doc-
tor
String Array Qualifications List of qualifications of the
doctor
String Address Address of the doctor
Date Time Date of birth To calculate age of the doc-
tor

Table 6: Doctor profile

4 Technologies
4.1 Hyperledger Fabric
Hyperledger Fabric is a blockchain framework implementation and one of the Hyper-
ledger projects hosted by The Linux Foundation. We are using it as the foundation for
developing our application with a modular architecture, Hyperledger Fabric allows com-
ponents, such as consensus and membership services, to be plug-and-play. Hyperledger
Fabric leverages container technology to host smart contracts called “chaincode” that
comprise the application logic of the system.

5
4.2 Hyperledger Composer
Hyperledger Composer is a set of collaboration tools for building blockchain business
networks that make it simple and fast for business owners and developers to create smart
contracts and blockchain applications to solve business problems. Built with JavaScript,
leveraging modern tools including node.js, npm, CLI and popular editors, Composer
offers business-centric abstractions as well as sample apps with easy to test devOps
processes to create robust blockchain solutions that drive alignment across business
requirements with technical development. We used it to interact with our underlying
blockchain.

4.3 JavaScript
As a multi-paradigm language, JavaScript supports event-driven, functional, and im-
perative (including object-oriented and prototype-based) programming styles. It has an
API for working with text, arrays, dates, regular expressions, and basic manipulation of
the DOM, but the language itself does not include any I/O, such as networking, stor-
age, or graphics facilities, relying for these upon the host environment in which it is
embedded. We used it to write our chaincode for the blockchain.

4.4 node.js
node.js is an open-source, cross-platform JavaScript run-time environment that executes
JavaScript code server-side. Node.js enabled us to use JavaScript for server-side script-
ing—running scripts server-side to produce dynamic web page content before the page
is sent to the user’s web browser.

4.5 npm
npm is a package manager for the JavaScript programming language. It is the default
package manager for the JavaScript runtime environment Node.js. It consists of a com-
mand line client, also called npm, and an online database of public and paid-for private
packages, called the npm registry. We used it to get packages for JavaScript.

4.6 HTML
Hypertext Markup Language (HTML) is the standard markup language for creating web
pages and web applications. Web browsers receive HTML documents from a web server
or from local storage and render the documents into multimedia web pages. HTML
describes the structure of a web page semantically and originally included cues for the
appearance of the document. We used it to create our user interface.

4.7 jQuery
jQuery is a cross-platform JavaScript library designed to simplify the client-side scripting
of HTML. We used it to send POST and GET ajax API calls to our back-end.

6
5 Learning
Blockchain: A blockchain is a continuously growing list of records, called blocks, which
are linked and secured using cryptography. Each block typically contains a crypto-
graphic hash of the previous block, a timestamp and transaction data. By design,
a blockchain is inherently resistant to modification of the data. It is ”an open,
distributed ledger that can record transactions between two parties efficiently and
in a verifiable and permanent way”. For use as a distributed ledger, a blockchain
is typically managed by a peer-to-peer network collectively adhering to a protocol
for inter-node communication and validating new blocks. Once recorded, the data
in any given block cannot be altered retroactively without the alteration of all
subsequent blocks, which requires collusion of the network majority.

Importance of blockchain: Blockchain technology has a large potential to transform busi-

ness operating models in the long term. Blockchain distributed ledger technology
is more a foundational technology—with the potential to create new foundations
for global economic and social systems—than a disruptive technology, which typi-
cally ”attack a traditional business model with a lower-cost solution and overtake
incumbent firms quickly”. The use of blockchains promises to bring significant
efficiencies to global supply chains, financial transactions, asset ledgers and decen-
tralized social networking.

Difference between public and private blockchain: The sole distinction between public
and private blockchain is related to who is allowed to participate in the network,
execute the consensus protocol and maintain the shared ledger. A public blockchain
network is completely open and anyone can join and participate in the network.
The network typically has an incentivizing mechanism to encourage more partici-
pants to join the network. Bitcoin is one of the largest public blockchain networks
in production today. One of the drawbacks of a public blockchain is the substantial
amount of computational power that is necessary to maintain a distributed ledger
at a large scale. More specifically, to achieve consensus, each node in a network
must solve a complex, resource-intensive cryptographic problem called a proof of
work to ensure all are in sync.

Importance of Electronic Health Records: EHRs and the ability to exchange health in-
formation electronically can help you provide higher quality and safer care for pa-
tients while creating tangible enhancements for your organization. EHRs help pro-
viding accurate, up-to-date, and complete information about patients at the point
of care. It helps securely sharing electronic information with patients and other
clinicians. It promotes legible, complete documentation and accurate, streamlined
coding and billing. It enhances privacy and security of patient data. It reduces
costs through decreased paperwork, improved safety, reduced duplication of test-
ing, and improved health.

7
5.1 Learning sources
• Hyperledger Fabric documentation

• Hyperledger Fabric on GitHub

• Hyperledger Composer documentation

• Hyperledger Composer on GitHub

• Blockchain online learning course on Coursera

• Medicalchain whitepaper

5.2 Challenges
• Since the blockchain technology is very new, the documentation available is limited
and it is not updated regularly

• There is no proper ”EHR using blockchain” sample use-case to follow

• Chaincode, Modeling, Access Control List and Query needs different syntactical
knowledge

6 Installation
6.1 Pre-requisites
The following are prerequisites for installing the required development tools:

• Operating Systems: Ubuntu 16.04 (64-bit)

• Docker Engine: Version 17.03 or higher

• Docker-Compose: Version 1.8 or higher

• Node: 8.9 or higher (version 9 is not supported)

• npm: v5.x

• git: 2.9.x or higher

• Python: 2.7.x

Then you can download the required development tools using the following commands:
$ curl -O https://hyperledger.github.io/composer/latest/prereqs-ubuntu.sh
$ chmod u+x prereqs-ubuntu.sh
$ ./prereqs-ubuntu.sh
Click here for more info.

8
6.2 Development Environment
1. Install the CLI tools: There are a few useful CLI tools for Composer developers.
The most important one is composer-cli, which contains all the essential operations,
so we’ll install that first. Next, we’ll also pick up generator-hyperledger-composer,
composer-rest-server and Yeoman plus the generator-hyperledger-composer.

(a) Essential CLI tools:

$ npm install -g composer-cli
(b) Utility for running a REST Server on your machine to expose your business
networks as RESTful APIs:
$ npm install -g composer-rest-server
(c) Useful utility for generating application assets:
$ npm install -g generator-hyperledger-composer
(d) Yeoman is a tool for generating applications, which utilises generator-hyperledger-
composer:
$ npm install -g yo

2. Install Playground: Browser app for simple editing and testing Business Networks:

$ npm install -g composer-playground

3. Install Hyperledger Fabric: This step gives you a local Hyperledger Fabric runtime
to deploy your business networks to.

(a) In a directory of your choice (we will assume /fabric-tools), get the .tar.gz
file that contains the tools to install Hyperledger Fabric:
$ mkdir ~/fabric-tools && cd ~/fabric-tools
$ curl -O https://raw.githubusercontent.com/hyperledger
/composer-tools/master/packages/fabric-dev-servers
/fabric-dev-servers.tar.gz
$ tar -xvf fabric-dev-servers.tar.gz
A zip is also available if you prefer: just replace the .tar.gz file with fabric-dev-
servers.zip and the tar -xvf command with a unzip command in the preceding
snippet.
(b) Use the scripts you just downloaded and extracted to download a local Hy-
perledger Fabric runtime:
$ cd ~/fabric-tools
$ ./downloadFabric.sh

Click here for more info.

9
6.3 Deploying a Hyperledger Composer blockchain business network to Hyperledger
Fabric
Click here for full guide.

7 Future work
• EHR structure can be modeled to suit specific disease or can be modeled on es-
tablished standards like openEHR

• Mechanism to access patient’s medical history in emergency situations

• Insurance companies can be given limited access for fairer claims

• Pharmacists can be added to monitor medical sales

10