CryptoBallot

CryptoBallot is a cryptographically secure decentralized end-to-end verifiable voting system meant for real-world elections. It is a "backend" service providing vote storage, cryptographic operations, and an API. It does not provide a user interface - although it is built to make creating a UI that interfaces with it easy.

It uses distributed key-generation for election encryption keys, blind-signing and an elGamal re-encryption mixnet for voter anonymity, and an optional blockchain backend for distributed transaction storage and verification. It supports all tally methods including write-in candidates.

Goals

Verifiable - the entire voting process should be end-to-end verifiable.
Ergonomic - Easy to use.
Fast - 5,000 votes per second for a single shard.
Scalable - Billions of voters. Unlimited votes per second with horizontal shard scaling.
Secure - Rock solid security guarantees, byzantine fault tolerance.
Distributed - Trust and redundency is distributed amongst an operator-selected set of trustees.

Current State

Under active development. Not ready for production use!

Road Map

Status¹	Feature	Notes
✓	Migrate from Go to Rust	🦀
✓	Distributed key generation / decryption	Uses cryptid.
✓	Blind-Signing (RSA)	Uses RSA-FDH
	Blind-Signing (schnorr)	Will replace current RSA blind-signing
✓	Re-encryption mixnet	Provides coercion resistant anonymity. Uses cryptid.
✓	Optional Blockchain backend	Uses Exonum
⚠	Support all tally methods	Uses Tallystick
⚠	REST frontend
⚠	End-User Device Verification	Uses Benaoh Challenge
	TypeScript / JS Client Library
	Dart Client Library (Android)
	Swift Client Library (iOS)

✓ means done, ⚠ means in-progress, blank means not started but support is planned.

Quick Start

# Install dependencies (Mac)
brew install jq pkg-config protobuf

# Install dependencies (Debian / Ubuntu)
sudo apt-get install build-essential jq libsnappy-dev libssl-dev \
pkg-config clang-7 lldb-7 lld-7 protobuf-compiler libprotobuf-dev

# Clone the repository
git clone git@github.com:cryptoballot/cryptoballot.git && cd cryptoballot
git checkout 0.5-beta1

# Install the server and command-line tools (go make some tea, this will take a while)
cargo install --force --path=cryptoballot_server
cargo install --force --path=cryptoballot_cli

# Make a directory to hold our cryptoballot database
mkdir $HOME/.cryptoballot

# Start the server in development mode (dev-mode will autogenerate and print the private-key). 
# Make note of the printed CRYPTOBALLOT_SECRET_KEY. We will refer to this as <secret_key>.
# WARNING: Don't use `run-dev` for production.
cryptoballot_server run-dev --blockchain-path=$HOME/.cryptoballot

# Example Output:
#   > Starting in development mode
#   CRYPTOBALLOT_SECRET_KEY=ddcd9d786ba3975f1c4ba215226f632c455cdd4de51d2183bc985f20f7abc3c9
#   > Starting cryptoballot server, listening on port 8080

# In another window, generate an election-transaction using the secret key from before
# This election is very basic with a single trustee, no authentication, and a single write-in-only plurality ballot-type
# Optionally visit http://localhost:8080/api/services/cryptoballot/transactions to see transactions
CRYPTOBALLOT_SECRET_KEY=<secret_key> cryptoballot election generate --post

# Make note of the generated election ID (we will refer to this as <election-id>)

# Create some votes
cryptoballot vote generate <election-id> "EASTER BUNNY" --post
cryptoballot vote generate <election-id> "SANTA CLAUSE" --post
cryptoballot vote generate <election-id> "EASTER BUNNY" --post
cryptoballot vote generate <election-id> "SANTA CLAUSE" --post
cryptoballot vote generate <election-id> "SANTA CLAUSE" --post

# As the election-authority, you decide when the voting is over and votes should be mixed and decrypted
# This can be automated by setting an end-time in the election transaction
CRYPTOBALLOT_SECRET_KEY=<secret_key> cryptoballot voting_end generate <election-id> --post

# After the voting is over, the server will automatically mix and decrypt the votes
# Optionally visit http://localhost:8080/api/services/cryptoballot/transactions to see transactions

# Do an verifiable end-to-end verification of the election and get the results!
cryptoballot e2e <election-id> --print-tally --print-results

Components

Core library

Add cryptoballot = "0.3.1" to your rust project's Cargo.toml file.

Command-line tool

Install Rust,
Run cargo install --path=cryptoballot_cli

Cryptoballot Server

Install Rust,
Install dependencies (see below)
Run cargo install --path=cryptoballot_cli

Dependencies

Cryptoballot Server depends on the following third-party system libraries:

RocksDB (storage engine)
libsodium (cryptography engine)
Protocol Buffers (mechanism for serializing structured data)

Other components (core library, command-line tools) don't require these dependencies.

Mac

brew install jq pkg-config protobuf

Debian / Ubuntu

sudo apt-get install build-essential jq libsnappy-dev libssl-dev \
pkg-config clang-7 lldb-7 lld-7 protobuf-compiler libprotobuf-dev

cryptoballot/cryptoballot