National Electronic Election Voting System (NE-EVS)

A secure, verifiable, and coercion-resistant electronic voting platform.

About

The National Electronic Election Voting System is a platform engineered to provide secure, verifiable, and coercion-resistant electronic voting. The system addresses fundamental challenges in e-voting, including voter privacy, ballot secrecy, and protection against vote-buying and coercion. It is built on a distributed microservices architecture and employs advanced cryptographic techniques to ensure that individual votes remain anonymous while allowing for a universally verifiable final tally.

Key Features

• Voter Anonymity: Uses RSA Blind Signatures to completely decouple voter identity from their cast ballot.

• Coercion-Resistance: Implements a "fake credentials" mechanism. Voters can cast decoy votes under duress using fake passwords; these votes are indistinguishable during the process but are discarded during tallying.

• Homomorphic Tallying: Utilizes the Paillier Cryptosystem to aggregate encrypted ballots. The final result is decrypted only once, ensuring individual vote contents are never exposed.

• End-to-End Verifiability: Supports individual verifiability (voters can confirm their vote was tallied) and universal verifiability (observers can audit the final encrypted tally).

• Receipt-Freeness: The system provides proof of receipt without providing a "receipt" that allows a voter to prove how they voted to a third party.

System Architecture

The system follows a services pattern with strict separation of concerns to enforce privacy.

Core Services

1. Registration and Identity Authority (RIA):
   • Acts as the "Registrar."
   • Manages voter registration, verifies NICs (National Identity Cards), and handles device binding.
   • Issues blind signatures for voting tokens
2. Token Registry (TR):
   • Issues one-time, random, anonymous tokens to voters.
   • Ensures tokens are generated anonymously and decoupled from user identity.
3. Voting Service (VS):
   • Acts as the "Election Trustee" and "Ballot Box."
   • Manages election lifecycles (candidates, timing) and accepts encrypted ballots.
   • Performs the final homomorphic tallying process.

Infrastructure

1. Database: PostgreSQL Master-Slave Cluster (AWS RDS) for high availability.
2. Gateway: Nginx Reverse Proxy for request routing and SSL termination.
3. Deployment: Dockerized services managed by PM2, deployed on AWS EC2.

Cryptographic Implementation

This project bridges academic theory with practical implementation using the following protocols:

Paillier Cryptosystem

• Used for Additively Homomorphic Encryption.
• Property:
  [ E(v_1) \times E(v_2) = E(v_1 + v_2) ]
• Votes are multiplied in batches to calculate the total count without decrypting individual ballots.

RSA Blind Signatures

• Based on Chaum’s blind signature scheme.
• Process:
  1. The voter blinds a token.
  2. The RIA signs the blinded token (authorizing it).
  3. The voter unblinds the signed token to obtain a valid signature on the original token.

Fake Credentials

• The RIA maintains two key pairs:
  • One for Genuine votes.
  • One for Fake votes.
• The Voting Service verifies signatures against both keys,
  but only counts ballots signed with the Genuine key.

Technology Stack

• Languages: Java 17 (RIA), Java 21 (Voting Service).
• Framework: Spring Boot (Gradle build).
• Database: PostgreSQL (AWS RDS Master-Slave Cluster).
• Infrastructure: AWS EC2, Nginx (Reverse Proxy/SSL), PM2 (Process Management).
• Other: OpenSSL for key generation
• CI/CD: GitHub Actions.

API Documentation

Registration Authority (RIA)

• POST /api/v1/account: Create a pending account.
• POST /api/v1/account/auth: Initiate login challenge.
• POST /api/v1/vote/sign: Request a blind signature.
• POST /api/v1/account/auth/fake: Generate fake credentials.

Voting Service

• GET /api/v1/public/elections: List active elections.
• PUT /api/v1/public/election/{id}/vote: Cast an encrypted vote.
• POST /api/v1/admin/election/{id}/tallying: Trigger tallying process (Admin).

Application Screenshots

This project consists of three applications. Below are key UI previews of each system.

1. Mobile App

Home Screen

Login / Authentication

Elections Page

Voting Interface

Election Results Page

3. Voting Admin Portal

Elections Page

Candidates Page

Election Page

Tallying Page

Setup and Deployment

The project is configured for deployment on AWS using GitHub Actions.

1. Prerequisites

• Java 17 and Java 21 installed.
• A PostgreSQL database instance.
• Nginx configured as a reverse proxy.

2. Buklding Services

• Build: ./gradlew bootJar.

3. Configuration

• Use ecosystem.config.js to define environment variables and service paths for PM2.
• Configure Nginx to route:
  • api.ria.evs.lk → port 9998
  • api.vs.evs.lk → port 8080

4. Running Services

# Services are managed via PM2
pm2 start ecosystem.config.js

Contributors

• 210077D - CHANDRAWANSHA J.P.S.A
• 210161F - FERNANDO K.J.R.K.
• 210383L - MEDDEPOLA M.A.C.T
• 210400N - MUTHUWANA M.A.N.R

Based on the academic e-voting scheme proposed by Aziz (2019).