1943

CHALLENGE 0

• Let's connect using the following command.

$ socat file:`tty`,rawer tcp:otp0.2023-bq.ctfcompetition.com:1337

• Once we are connected, we are greeted with the following screen.

• The password we have to enter is Sidney.

• The Fire message is about a fire while the Important message contains information about the Venona project.

• If we try to access the Spam message we are prompted to enter the secret key that we have been provided with.

VGhlIFZlbm9uYSBwcm9qZWN0IHdhcyBhIFVuaXRlZCBTdGF0ZXMgY291bnRlcmludGVsbGlnZW5jZSBwcm9ncmFtIGluaXRpYXRlZCBkdXJpbmcgV29ybGQgV
2FyIElJLg==

• The double equal signs is a common indicator of Base64 encoding.

• Let's decode the key using Cyberchef.

The Venona project was a United States counterintelligence program initiated during World War II.

• Some more information about the Venona project.

• We can now access the Spam message.

Flag

CTF{Ace_of_Spies}

CHALLENGE 1

CHALLENGE 2