Christian Leipold/ Oktober 18, 2022/ IT-Security, Write-Ups/ 0Kommentare

Pandora´s Box

TYPE: CRYPTOGRAPHY

Challenge

Pandora´s box, we have found it! Even better, the last travelers knew the numbered code to get in but they couldn't figure out the transcription. Figure out the the transcription's translation to find the flag!

Download Image
SHA1: 8e613787658d2d5828448aa182e2bb4904c124a8

Submit the flag as: flag{word_word_word_word}

Solution

Given was the follwing image

So it looks like that
GUVZ QGZ PFV TVB is the cyphertext and the numbers 3686 526 814 518 above (exactly the same amount and even the distances look like they match) should help decode the message.

3686 526 814 518
GUVZ QGZ PFV TVB

Let´s take the alphabet and try working with the numbers

A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z

If we talk about Caesar cipher or ROT13 we move the letter to the right (one or more).
By the way: A colleague always made a joke about it and told me that he always uses the double ROT13 (think about it) 🙂

But on the picture you can see an arrow pointing to the left. So let's try to move the letter to the left according to the number.

So we start with the G and the 3:
G - 3 = D
U - 6 = O
V - 8 = N
Z - 6 = T

Q - 5 = L
G - 2 = E
Z - 6 = T

P - 8 = H
F - 1 = E
V - 4 = R

T - 5 = O
V - 1 = U
B - 8 = T (At the end, one more special feature. When you reach A, just jump to Z.)

flag{dont_let_her_out}