SaintCon 2015 PreCTF - 4

-- CIPHERTEXT --
AEBRVHWWMQHURVWFFIKVYFUCDG
To Decrypt this Message, you will need to learn how a US President encrypted messages while in Paris France.

The PSK sequence you need to know is:
5,24,4,20,23,2,11,22,19,15,10,18,16,1,14,3,25,9,6,12,26,7,13,17,21,8

Realizing this was a terrible idea, went back to the PDF to realize that there are numbers at the top of the 2x2 grid. It then became obvious that the PSK given is the order of the tumblers needed to solve the ciphertext.

The solution script does the following:

* Extracts each individual tumbler
* Arranges the tumblers in order based on the PSK
* Rotates each tumbler to match the ciphertext
* Prints every resulting line

Upon execution, we are given the following result:

Checking out the website:

I don't think I was the first, but it was a great challenge nonetheless! Thanks to @saintcon for the pre-challenge and looking forward to more puzzles in the future.

## Final solution

```python

from collections import deque

ciphertext = 'AEBRVHWWMQHURVWFFIKVYFUCDG'
cipher = '''
R C X G O R U Q P T U V X L Z N Q S P V P I T M K E
X K N W G P D H X N G X P O B Q W O O O A P H Y Q Q
A W K R W Z T Y Y G Y J H F E D L T Z A R G Z A T F
Q Y V J R J G J E I N D D G Q J H A L C Q Z X K G D
I P J C F L C Z S M T Y B K W V D E R I S B S L M B
H X C B L W R C J V Q W C X O B T X C E X W R H W P
O V H D U T X R T E F O V C M L G U Q J B E O Z C S
V M E V Y X L U Q O H F E I U T E M Y L F L W D R C
L E W Z N B F G B Q I B Y Q H F K R T F Y Y Q U P X
Y S I N E S Y T A A X E K D C W C N M B G J A P S V
T L F F D I M W D K W A O B N A V F X Y M D K I J R
F T G X J C I K Z B M T Q U J C B L W N C X L G D L
U N B T Z F N B O Z B R J T D S F Q V R I A G O L J
W D M K V H W A R X C P L M L Z J C S S J U U N B U
N G Q Q C V S L U Y J C N V K P O I U D L O J S Y N
M B Y U Q A E N G C V N U E V U R B B Z W N E W A M
C A S E A M H V V S P Q G Z I R S J I M T K B R O Z
J O R P X G B D K L S U F H Y M I H G T Z C M E N K
D F P H K K J E F R A L Z A R K N P E Q D F D C E W
K H U S M N O X H H Z I W R P H Z V F P E Q Y X I H
Z U T Y B D P P C P E Z I W F Y X W H H U V V J U G
P R D L S U V I L U R S S N T G Y Y D U H R N Q X Y
B I O I P O Q S N D D G R S G E M D A W K S C B F O
S J L M H Q K M W J L H T Y S O P G K X N T I F H A
G Z A O I Y Z F I W K M M P A I A K N K V M F T V I
E Q Z A T E A O M F O K A J X X U Z J G O H P V Z T
'''

# Convert grid to 26 individual tumblers
cipher = zip(*[x.split() for x in cipher.splitlines()[1:]])

tumblers = []
final = []
psk = [5,24,4,20,23,2,11,22,19,15,10,18,16,1,14,3,25,9,6,12,26,7,13,17,21,8]

# Create cryptex
for index in psk:
    tumblers.append(cipher[index-1])

# Rotate tumblers to read ciphertext
for index,tumbler in enumerate(tumblers):
    tumbler = deque(tumbler)
    while tumbler[0] != ciphertext[index]:
        tumbler.rotate(1)

    final.append(list(tumbler))

# Flip 2D array to read everyline
"""
a b
c d
 |
 v
a c
b d
"""
final = zip(*final)

# Print all
for f in final:
    print ''.join(f)