Protect DeFi with Submarine Frontrun Protection

Submarine frontrun protection is a mechanism used to protect decentralized finance (DeFi) traders from being front-run by other traders or bots. Front-running occurs when a trader places a trade just before another trader's larger trade in order to profit from the price movement that the larger trade is likely to create.

There are various ways to implement submarine frontrun protection, but one common approach is to use a smart contract that executes trades on behalf of the trader. Here is an example of how to code a simple submarine frontrun protection smart contract:

pragma solidity ^0.8.10;

interface IUniswapV2Router02 {
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
}

contract SubmarineFrontrunProtection {
    address public immutable uniswapV2Router;
    
    constructor(address _uniswapV2Router) {
        uniswapV2Router = _uniswapV2Router;
    }
    
    function executeTrade(
        address tokenIn,
        address tokenOut,
        uint amountIn,
        uint amountOutMin,
        address to,
        uint deadline
    ) external {
        require(msg.sender == tx.origin, "Only externally owned accounts allowed");
        
        address[] memory path = new address[](2);
        path[0] = tokenIn;
        path[1] = tokenOut;
        
        IUniswapV2Router02(uniswapV2Router).swapExactTokensForTokens(
            amountIn,
            amountOutMin,
            path,
            to,
            deadline
        );
    }
}        

This smart contract uses the UniswapV2Router02 interface to execute trades on the Uniswap decentralized exchange. The executeTrade function takes in the token to be sold (tokenIn), the token to be bought (tokenOut), the amount of tokenIn to sell (amountIn), the minimum amount of tokenOut to receive (amountOutMin), the address to send the bought tokens to (to), and the deadline for the trade (deadline).

The function then checks that the caller is an externally owned account (EOA) using the tx.origin variable. This is because smart contracts can be called by other contracts, and we only want to allow EOAs to use this protection mechanism.

Finally, the function constructs a path array with the token addresses, and calls the swapExactTokensForTokens function on the UniswapV2Router02 interface to execute the trade.

This smart contract can be used by DeFi traders to protect themselves from front-running by other traders or bots. They can simply call the executeTrade function on this contract instead of directly interacting with the UniswapV2Router02 interface.