anonymous-voting

Setting up environment

Ganache

Install Ganache CLI tool for a fast, reliable local testnet.

npm install -g ganache-cli

Solidity

Install Solidity compiler.

brew update
brew tap ethereum/ethereum
brew install solidity

Also install abigen tool

go get -u github.com/ethereum/go-ethereum
cd $GOPATH/src/github.com/ethereum/go-ethereum/
make
make devtools

Running Ganache Testnet

The mnemonic "ces27" is added for deterministic account scheme generation.

ganache-cli -m "ces27"

The generated accounts should be the following

(0) 0xffae362fb776ce8b5A13D2b1ae679ECa0FD4A64e (100 ETH)
(1) 0x2164952E6Cd3214f67170F27209E8C22C4F70efc (100 ETH)
(2) 0x499f9d7Ba289B22cF71341a0B55cdb5eD929ac14 (100 ETH)
(3) 0xe199782E066b061c29097da5471707395126aF75 (100 ETH)
(4) 0x1eAD322628D33dc38660b15331AEBc5295D47278 (100 ETH)
(5) 0x1746EBe4a6FC1FB7081c9451779F3828B1b5F013 (100 ETH)
(6) 0x7726E00348b29Db7FDdC4e0100f143EAd01C1e76 (100 ETH)
(7) 0xdC27Ee49a65432e19CA21f240dac7C3A233375Ef (100 ETH)
(8) 0x7D4aFf221c308a00F1Ef15bb106125E8BfFe9cfE (100 ETH)
(9) 0x5eC1c5660BfF1012B061030E0bA5e3A07B124C62 (100 ETH)

The private keys are the following

(0) 0xcbed89197463cd2cfc71c2fe196989d844e56363269c11fc1b1fe510ed95f431
(1) 0x0ac0753be57e786048d3b2c09209485e290d88ba8d4a8cb5037dc79735f4fbd2
(2) 0xada477acd4db4d709a7ec2592c932ac3b19f948a93f468fb7c3c485a7a0b7b75
(3) 0x3705b1238edfa988aaecca5401df14abb11a7861e36b9996a80e57b0e3e301b4
(4) 0x3706b74cfeaf397c7c704c35f91711670e4124bd355b70d1b39679487ccbbb79
(5) 0x85f70d9a2f4dcb3cda5747fbec8555e7bb33cf47a67d195e46a5b0bbe4a368ab
(6) 0x33161f95f9c029d70e542d7bd13e1bcb677b8cb18436b95d0ac651841e68d0c5
(7) 0xa9a76319b6e5dbcf8afe2db55e76ab91a390efce633488982ecae9d625e3eb2a
(8) 0x7b06a0b3421c2447126477088e38cf32bc925717f74b3803b521ddc126b088b8
(9) 0x47b13371fb72c0f60f7dfa8c76fed2b39e8f2bdaefb9b3b42199251a2f898cad

Compiling contracts

Compile the contracts.

solc --abi ./contracts/AnonymousVoting.sol -o bin
solc --bin ./contracts/AnonymousVoting.sol -o bin
abigen --bin=./bin/AnonymousVoting.bin --abi=./bin/AnonymousVoting.abi --pkg=eth --out=./pkg/eth/voting.go

Deploying contracts

Now, we have to deploy our contract in the blockchain. For that, we have to specify an address with ETH to make the deployment. For simplicity, just choose 0xcbed89197463cd2cfc71c2fe196989d844e56363269c11fc1b1fe510ed95f431

go run ./cmd/deployer.go cbed89197463cd2cfc71c2fe196989d844e56363269c11fc1b1fe510ed95f431

Everytime this script is executed, a new contract is deployed at a different address. If it's the first transaction in the blockchain, the addresses should be the following.

Connected to Ganache
Contract deployed!
  contract address: 0xd1285556883015FFFFe2C44227918E112290bdF0
  transaction hash: 0x9dd8f6d4eea464805ae49bb1baae78905545246ee22886a2598e488567642707
Candidate count: 0
Voter count: 0

Voting scheme

Key managers

For the anonymous voting scheme, we need to set two key managers to generate the first public key to our voting. They are supposed to deposit an amount of Ethers in the contract to make sure they reveal the secrets at Tally Phase. This incentivates the election to finish eventually.

We need to set a name and a random key (0 for random generation, a real number for reproducibility). They announce rA * G and rB * G to the contract, and can compute rA * rB * G. Then, in the Tally Phase, they reveal rA and rB so that the result can be computed.

go run ./cmd/manager/main.go Alice 1

go run ./cmd/manager/main.go Bob 2