Dec 2: Free Giveaway

Challenge

the keys are the key

Today, Santa has a free giveaway for you:

DK16[OEdo[''lu[;"Nl[R"D4[2Qmi

Solution

Seems clear that that string represents the flag, vigenere cipher?

D is 4th letter in alphabet, if you shift 4 further you get H, K is eleventh letter and if you shift 11 further you get V ..but how to handle special characters? [ needs to be shifted to -

This almost works..? (but seems too random to just exclude number and not keep ascii ordering of chars ..I dunno, it’s day 2, probably overthinking?)

hint is the key is in the keys ..maybe only shift those symbols that you need the shift key to type? (so leave lowercase and numbers as is, shift uppercase and some other symbols?)

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import string

flag="DK16[OEdo[''lu[;\"Nl[R\"D4[2Qmi"
alphabet="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz123456789 !\"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~ "

pt=''
count=0
for c in flag:
    if c in string.digits or c in string.lowercase:
        pt+=c
    else:
        pt += alphabet[((alphabet.find(c)+alphabet.find(flag[count]))+1)%len(alphabet)]
    count +=1

print pt

Turns out it is just a translation from qwerty to dvorak. Inverting that gives us the answer and explains the hint mentioning “keys”:

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from string import maketrans

QWERTY = '''-=qwertyuiop[]sdfghjkl;'zxcvbn,./_+QWERTYUIOP{}SDFGHJKL:"ZXCVBN<>?'''
DVORAK = '''[]',.pyfgcrl/=oeuidhtns-;qjkxbwvz{}"<>PYFGCRL?+OEUIDHTNS_:QJKXBWVZ'''
TRANS = maketrans(DVORAK, QWERTY)

flag="DK16[OEdo[''lu[;\"Nl[R\"D4[2Qmi"

print ''.join([x.translate(TRANS) for x in list(flag)])

Flag