bookmark_borderCCTF 4 Hacktivity Writeups 1.

We have received many requests for the CCTF game writeups. Here is the first one, the challenge was called “BIPolognese”. Be careful, spoilers follow.

Challenge: BIPolognese

BIPolognese (100 points)
Crypto Wojack (beginner)

Crypto Wojack was considerate again and made a cold backup of his wallet seed so Bogdanoff can't hak it again.
Meanwhile, he was lost in eating ₿10.000 pizza.

Look at that picture! Can you get the account address?

The hints

  1. The challenge’s name itself suggests a BIP seed
  2. Cold backup
    • These are copied somewhere offline, but before it is shown on the screen
  3. Doing something during eating
    • Crypto Wojack is doing something with the BIP seed and a wallet
  4. Look at the picture
    • You will find the BIP seed on the right laptop’s screen

The solution

Note the BIP44 seed words from the screen, open a web browser, install MetaMask.

After you have installed it, this screen will appear:

Choose the “Import wallet” option and use the seed phrase from the picture.

You find that the wallet it empty, but the flag is the first address as mentioned in the Rules.

Writeup by: six