HeroCTF v3 2021: Atoms

Atoms

Category: Steganography

50 points

Dmitri sends us this message, will you be able to retrieve the secret message hidden inside?

MtMdDsFmMdHsMdMdUuo

Format : Hero{}
Author : xanhacks

Solution

Given string is actually a list of chemical elements. I’ve matched them with the atom numbers and retrieved flag as below.

Mt => 109
Md => 101
Ds => 110
Fm => 100
Md => 101
Hs => 108
Md => 101
Md => 101
Uuo => 118

flag = [109, 101, 110, 100, 101, 108, 101, 101, 118]
print("Flag: Hero{{{}}}".format(''.join(chr(i) for i in flag)))

Output:

Flag: Hero{mendeleev}

Flag

Hero{mendeleev}