Why?

The only way to defeat spam is to raise the cost of spamming. This can be done two ways: increasing the work needed to submit content (captcha, email verification, IP blacklisting, ID verification) or directly using Damage Deposit. As methods like CAPTCHA increasingly fail due to advancements in ML-based solving and solving farms, user privacy is constantly eroded as identifying humans from bots becomes increasingly difficult. DamageDeposit provides an alternative by directly increasing the cost of spamming while reducing the impact on legitimate users, using an Ethereum smart contract to collect a deposit that can be confiscated by the service operator in cases of abuse. This also allows spam removal to become a profitable undertaking rather than a financial burden.

Usage

Configuration

Edit scripts/deploy.js with the appropriate contract values for deposit amount and withdrawal hold period. Withdrawal period should be set long enough that abuse can be detected before the user withdraws the deposit.

const withdrawPeriod = 5;
const depositRequirement = "0.001";

Compiling

npm install
npx hardhat compile

Deploying The Contract:

To deploy the smart contract to the Ethereum network you need a network provider, either an RPC provider like Infura or Alchemy (both have free options) or your own Ethereum node. You will also need enough Ethereum to cover gas fees for deploying the contract.

Point the URL to your mainnet provder by editing hardhat.config.js and adding your RPC URL and wallet private key:

    mainnet:{
      url:"https://mainnet.infura.io/v3/1234567890abcdef",
      accounts: ["0xbbbbbbbbccccc2222222222111111111aaaaaaaaaa0000000000"]
    }

The owner of the contract (private key) will have access to the admin functions, most importantly deposit confiscation. The Ethereum account that deploys the contract will be the first contract owner and can be changed later. Keep this account safe, otherwise admin functions cannot be performed.

Other methods of configuring the connected wallet can be found here.

Deploy the contract
npx hardhat run scripts/deploy.js --network mainnet

Deploying to Test Network

The contract can also be deployed to the Sepolia test network to test live functionality without using real Ethereum. Complete the Sepolia network config in hardhat.config.js with a Sepolia provider (Infura, Alchemy) and wallet containing Sepolia ETH:

    sepolia:{
      url:"https://sepolia.infura.io/v3/1234567890abcdef",
      accounts: ["0xbbbbbbbbccccc2222222222111111111aaaaaaaaaa0000000000"]
    }

Then deploy the contract:

npx hardhat run scripts/deploy.js --network sepolia

Interacting with DamageDeposit

A demo interface is included in the interface/ directory. After deploying your contract, you can load the interface to interact with it:

cd interface  
npx http-server

The page will be available at http://localhost:8080/. You will need a browser-connected Ethereum wallet (Frame, Metamask etc) to sign the transactions.

Basic Workflow

1. User deposits Ethereum to the contract.
2. User interacts with protected infrastrucutre (forum, service etc) signing their submissions with their Ethereum wallet.
3. Service checks contract for valid user deposit before accepting content.
4. User signals intent to withdraw when interaction with target service ends.
5. Service admin (forum admin, chat moderator, website operator etc) checks content for rule violations and confiscates user deposit if needed.
6. After timelock period ends, user can withdraw their deposit (if not confiscated).