Clinical Trial Management Using Blockchain Technology

Motivation

Clinical trials currently build on an inefficient recruitment process due to slow communication between the patients and medical professionals. A solution for this problem is to share electronic medical records (EMRs) via an online platform, but standard approaches cannot ensure the immutability of the medical history. This web application is a peer-to-peer platform that does not rely on trust. Using blockchain technology, all EMRs are stored tamper-proof by logging uploads inside a smart contract. On top of that, it employs proxy re-encryption to allow access control.

Requirements

Make sure that you have installed the following software:

• Ganache
• IPFS
• MetaMask
• NPM
• Python (at least version 3.5)
• pyUmbral

Setup

Ganache

Inside the Ganache directory, start the blockchain:

sudo npm start

Repository

Clone the repository:

git clone https://github.com/janetzki/Clinical-Trial-Management-Using-Blockchain-Technology

Navigate into its main directory, then install the requirements:

sudo npm install

Smart Contract

Initialize the smart contract:

cd truffle
sudo truffle compile
sudo truffle migrate

(Troubleshooting: If the migration step fails, delete the truffle/build/ directory and try again.)

IPFS

Start the IPFS daemon:

ipfs init
ipfs daemon

Allow local requests to the IPFS daemon:

ipfs config --json API.HTTPHeaders.Access-Control-Allow-Origin '["http://localhost"]'

Key Management System

From the main directory, start the key management system:

python kms_server.py

Web Server

Start the web server:

sudo npm start

You can now access the platform at localhost:80 in your browser.

Use MetaMask to connect to the Ganache blockchain. Do not forget to reset your accounts if you used them before.

Usage

First, log in as a patient or medical professional by clicking the respective button. You should see a new web page.

As a Patient

Note that the following steps require to interact with MetaMask.

• Click "Generate keys" to generate a new key pair and store the secret key at a safe location. The public key is stored on the blockchain and will be loaded when you refresh the window. You need to re-enter the secret key manually.
• Click "Browse" to select a medical record. Examples can be found in examples/records/. Click "Upload medical record" to upload it to the platform.
• Click "Show records" to see a list of the hash pointers to your uploaded records. Note that it might take some seconds for a new record to show up since a new block has to be mined. Click the link to see the encrypted content in a new tab. Click "Decrypt" to see its original content.
• You can grant access to a medical professional, who already has a key pair. If not, first log in as a medical professional as described below. Then enter its blockchain address into the text field and click "Grant access". In MetaMask, you can choose the files for which you want to grant access.

As a Medical Professional

Note that you need to use another blockchain account in MetaMask to log in as another user. This works best with two different browsers.

• Like for the patient, generate a key pair and store the secret key at a safe location.
• Enter the blockchain address of a patient that granted access to their medical records.
• Click "Show records" to see a full list of all accessible medical records for this patient. You can use "Decrypt" and the link in the same way as the owner of the record.

Test the Smart Contract

cd truffle
truffle test

Note for Developers

If you make changes to web_pages/user.js, apply the tool browserify to make it usable by browsers:

browserify web_pages/user.js > web_pages/user-browser.js