Vitalik

Description

Vitalik's creation uses a hashing function. Find our path to the mapping for nothing.

And There's Nothing

Let's start by figuring out who Vitalik is and what is their "creation"

Google searching reveals a man named Vitalik Buterin, founder of Ethereum, which is a blockchain

Man is busy

As per the description, this Ethereum uses a hash function, so let's try to find what it is

As we can see, it uses Keccak-256

Keccak-256 Online

This hash function is very impressive, as it's able to hide the length of the message. For the next bit, I stewed about what Find our path to the mapping for nothing meant

I tried encoding "path" as well as the whole message, then shoving it into the uwctf{...} format, though that was certainly not correct

I was stumped.

It wasn't until I played around with Keccak-256 that I realized that even the empty string hashes to something, and the word "path" had a very different meaning...

The empty string, or "nothing", hashes to c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470

We can add this to the "path" of the CTF website, which will immediately download a file

https://ctf.csclub.uwaterloo.ca/c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470

Open it with any text editor to get the flag

Flag

uwctf{6c48c02b6682151e}