So GCHQ have just released a new competition that’s fun to do in downtime. It’s hosted here: https://canyoufindit.co.uk.

It give’s you the following cipher and no information about it:
Screen Shot 2013-09-13 at 16.22.04

After looking at the code it seems that the letter Q is very common. I tried various tricks such as applying ROT13 ROTn and so on but couldn’t get it to reveal anything clear.

I then tried to take every x letter and when i got to 10 I was about to give up. I decided to go a little further and at a number a little higher than 10 I figured out the code was based on a rotational design. I haven’t a clue what it’s called but i guess this works in a similar way to a cipher stick?
Skytale

Well here’s the code for those that want the answer but I suggest figuring it out yourselves (p.s. This has been modified from my original version in order to pretty’fy things)…

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#!/usr/bin/env python
# canyoufindit.co.uk part 1
import sys
print "[+] Origional cipher:"
cipher="""AWVLI QIQVT QOSQO ELGCV IIQWD LCUQE EOENN WWOAO
LTDNU QTGAW TSMDO QTLAO QSDCH PQQIQ DQQTQ OOTUD
BNIQH BHHTD UTEET FDUEA UMORE SQEQE MLTME TIREC
LICAI QATUN QRALT ENEIN RKG"""

print cipher

print "\n[+] No spaces or newlines:"
cipher=cipher.replace(' ','').replace('\n','')
print cipher

print "\n[+] Swap Q for ' ':"
cipher=cipher.replace('Q',' ')
print cipher

clear=""

rotation=13
for i in range(rotation):
    for pos in range(len(cipher)):
        if pos % rotation == i:
            clear+=cipher[pos]

print ""
print clear.replace('DOT','.').replace('SLASH','/')

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