Tyrael's Crypto

Here are a bunch of simple crypto challenges:

Question 1:

Tyrael has chosen you to be a hero of the Horadrim! He has encoded several messages and it is your job to decode these messages to receive your instructions (Flags!). Here is the first one he left for you to decipher:

U3RvcCEgVGhlIGJlYXN0IGNvbnRhaW5lZCBoZXJlaW4gc2hhbGwgbm90IGJlIHNldCBmcmVlIOKAlCBub3QgZXZlbiBieSB5b3UuIGdjdGZ7dGhlX3JldHVybl9vZl9ldmlsfQ==

Question 1 Answer:

This one is pretty easy to spot that it looks like base64, throwing this into cyberchef or other base64 decode tool we get this as a decoded message:

Stop! The beast contained herein shall not be set free — not even by you. gctf{the_return_of_evil}

Question 2:

Tyrael saw that the first message was too easy for The Prime Evils to decode, so know he must step up his game! If it wasn't Mephisto or Diablo... then it must have been Baal... or one of them... Here is the second message he left for you to decipher:

H!`l!`!v`oedsds:!H!i`wd!rddo!lnsd!ui`o!lnru!vntme!dwds!hl`fhod/!Ui`u!hr!ldsdmx!lx!o`utsd/!fbugzuxs`dm^hr^lx^o`ld|

Here is a CyberChef Recipe

Question 2 Answer:

The key to this challenge was in the line: If it wasn't Mephisto or Diablo... then it must have been Baal... or one of them... With that last bit or one can clue us in that we can try to xor the message with a key of 01

I am a wanderer; I have seen more than most would ever imagine. That is merely my nature. gctf{tyrael_is_my_name}

Here is a CyberChef Recipe

Question 3:

If it was good enough for Julius Caesar then it should be good enough for Tyrael right? Hopefully this one will last longer than the 18 days ride it will take to reach you.

Here is the next code for you to decipher:

Eqbpwcb i jmoqvvqvo, bpmzm qa vw mvl. Em ucab abizb awumepmzm, ivl bpqa xtikm qa ia owwl ia ivg. okbn{emtkwum_ocizlqiv}

For this one we can look at the end and can see that there is a flag there. So, with that there are a few things we can look at as options in order to decode this problem.

1. we see that the {} are still there so that will limit a bunch of options

2. okbn = gctf

From these two facts you could think of a ROT-13 type of substitution, but if you try it out. it still turns up gibberish. CyberChef Recipe

It does look like a good start and the Caesar clue puts us on the right track. Looking at the clue a little closer we see something about 18 days, so lets try instead on 13...18 on the Rotation.

Question 3 Answer:

Without a beginning, there is no end. We must start somewhere, and this place is as good as any. gctf{welcome_guardian}

Here is the CyberChef Recipe