E-Voting using BigchainDB

This is an early version of a demonstrator of BigchainDB based architecture.

The data are collected and inserted into the blockchain using a web application written in AngularJS.

The data visualization is provided via web browser using Plotly library.

The plotted graphs are retrieved by querying MongoDB.

The graphic representation is provided through a Node.js application, which makes use of Express.js as a middleware web framework to allow the communication between web browser and database.

The following components are required:

• BigchainDB 2.2.1,
• MongoDB 3.4 or newer,
• Tendermint 0.31.5 ,
• Node.js.

This demonstrator has been developed using Ubuntu 18.04.

1.Backend

Bigchaindb

To install BigchainDB please follow the steps indicated in [1], avoiding the usage of NGINX.

These are the steps performed to install the version 2.2.1:

1.Installing pip for python3:

sudo apt install python3-pip

2. use pip3 to install bigchaindb

sudo pip3 install bigchaindb==2.2.1

configure bigchaindb running:

bigchaindb configure

MongoDB

To check if the version in the repository is correct:

apt-cache policy mongodb

After verifying that is the correct one, to install it:

sudo apt install mongodb

To check if mongodb is running:

systemctl status mongodb

Tendermint

To install tendermint we also installed unzip.

sudo apt install unzip

then we used wget to download the tendermint zip file.

unzip tendermint_v0.31.5_linux_amd64.zip

mv the directory to /usr/local/bin

sudo mv tendermint  /usr/local/bin

Initialize it with

tendermint init

To allow members to connect each other is fundamental to configure the file config.toml as explained in [1]

Monit

Monit is used to run and monitor tendermint and bigchaindb. It will restart them if they crashed.

sudo apt install monit

As explained here, you will be able to run the bigchaindb-monit-config script, which will be in your PATH. Running the script is required to build a configuration file for Monit:

bigchaindb-monit-config  

To run monit:

monit -d 1

2.Frontend

Data entry: vote choice

Through the page frontend_vote.html, voters make their choice.

The Javascript code shown here is called inside frontend_vote.html, and through that code the data are inserted in the blockchain in JSON format.

Graphical visualization

To visualize the data inserted in the blockchain, we used a node.js application installed on one of the nodes.

To install node.js:

sudo apt install npm

These packages are required by our application:

npm install bigchaindb-driver@4.1.0
npm install base-x@3.0.4
npm install bip39@2.5.0
npm install mongodb@3.0.4
npm install express -–save
npm install jquery

The code of our node.js application can be found here.

To interact with the node.js application there are 2 Javascripts files, calculate.js and myFunctions.js, that are loaded into a html page.

Here there is a video which shows how the interaction with the blockchain occurs, visualizing with a graph the status of the vote.

Experiments

In the test directory there are log files collected during the experiments. Here are some videos where part of the experiments are shown:

10 nodes experiment, configuring and running 10 nodes. This video shows how 10 nodes are configured, using a bash script that basically sets the moniker in the config.toml file, distributes the genesis.json file on all nodes and runs monit, which is used to run tendermint and bigchainDB, and monitor its running. 10 nodes configring and running

10 nodes experiment, running the command monit status to check if bigchaindb and tendermint are running correctly: 10 nodes monit summary