02.Guess the secret number

2023-06-23 20:22:15

**#**01.Capturetheether CTF# Guess the secret number

## topic

1 | pragma solidity ^0.4.21; |

## analyses

we need to guess a number which returns `0xdb81b4d58595fbbbb592d3661a34cdca14d7ab379441400cbfa1b78bc447c365`

after keccak256(). we can brute force it because the type of guess numer is uint8 which means there are only 256 probabilities.

## solution

1.find the correct number off-chain

1 | const {ethers,utils} = require("ethers") |

2.call `guess(uint8)`

with the parameter “170” and 1 ETH