CSEM CTF - Cryptography Challenges

Can you crack these cryptographic puzzles?

Easy Challenges

Hidden in Plain Sight

Difficulty: Easy

Our agent intercepted this strange message. It seems to use multiple encoding layers:

VTFSVlVsTkZRM3RrYjNWaWJHVmZkSEp2ZFdKc1pWOWlZWE5sTmpSOQ==

Hint: Sometimes things are not what they seem at first glance. Look closer at the patterns.

Ancient Whispers

Difficulty: Easy

An ancient scroll was found with this text. The key to decrypt lies in the number XIII:

FGHEFVP{gur_cngu_bs_gur_jneebbe_vf_abg_rnfl}

Hint: The Romans had their secrets.

Medium Challenges

The Mathematician's Note

Difficulty: Medium

A mathematician left this encrypted message. The key is hidden in this sequence: 2, 3, 5, 7, 11

8-19-21-18-19-5-3{13-1-20-8-19-95-19-5-3-18-5-20-19}

Hint: Prime numbers hold special properties in cryptography.

Binary Riddle

Difficulty: Medium

We found this binary sequence, but something seems off about it:

01010011 01010100 01010101 01010010 01010011 01000101 01000011 01111011 00110010 01011111 00110100 01011111 00110110 01011111 00111000 01111101

Hint: The answer might not be as straightforward as ASCII.

Hard Challenge

The Quantum Vault

Difficulty: Hard

Break into the quantum vault:

Public Key (e): 65537

Modulus (n): 882564595536224140639625987659416029426239230804614613279163

Encrypted Flag: 77578995801157823671636298847186723593814843845525223303932

Hint: The modulus has a special property related to Fermat numbers.