I need help with the following code where I'm given the keccak256 of a parameter and need to reverse it to find the parameter to solve the challenge

contract LessonFive is AFoundryCourseChallenge {
    error LessonFive__WrongPassword();

    bytes32 public constant EXPECTED_BYTES = 0xb68fe43f0d1a0d7aef123722670be50268e15365401c442f8806ef83b612976b;

     * Use all the help you can on this one! Google, AI, friends, peeranha, ethereum stack exchange, etc. 
     * Hint: It's a very common...
     * @param password - A string that when you keccak256 it will return the `EXPECTED_BYTES`!
     * @param yourTwitterHandle - Your twitter handle. Can be a blank string.
    function solveChallenge(string memory password, string memory yourTwitterHandle) external {
        if (keccak256(abi.encodePacked(password)) == EXPECTED_BYTES) {
        } else {
            revert LessonFive__WrongPassword();

1 Answer 1


keccak256 is a one-way cryptographic hash function, which cannot be decoded in reverse. It is a trick! Anyhow, solution below:

const EXPECTED_BYTES = keccak256('password')`

You can use this tool as a reference:


Enter 'password' and generate the keccak256 online.

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