CIPHER PUZZLE
CACHES DECODED -
BIFID
Some cachers dread mystery/puzzle caches, especially if the puzzle is some sort of cipher.
With this new series, I would like to try to shed some light on ciphers found in
some puzzle caches out there using this cache series to show you how to identify
the different ciphers and how to solve them. I am calling this series "Cipher
Puzzle Caches Decoded". This is sort of a reboot of a series I did 14 years ago
that ended up with just a few caches in the series.
Before we jump
in, lets first go over some cipher terminology that will be helpful in solving
ciphers:
PLAINTEXT:
Is a message or text that
has not been encrypted.
CIPHERTEXT:
Is a message or test that
HAS been encrypted.
KEY or KEY TEXT:
Is a keyword, letter, or
phrase that is used to make ciphered text more difficult to solve.
CODE:
Is a kind of substitute language that is
used to hide or conceal the word in question. An example would be something like
"Pizza dinner tonight @ 5 PM" could be worded as the frisbee hits the table at 5
PM. Substituting the word "pizza" for frisbee changes the meaning of the
sentence for those who know what the code is.
BLOCK CIPHER:
A block cipher breaks a message into
a set number of pieces and encrypts one piece or block at a time.
MONOALPHABETIC CIPHER:
This is a cipher that uses a single
alphabet. Letters are usually just replaced with another letter in the same
alphabet like replacing the letter "A" with the letter "N". Caesar, Pigpen and
Playfair ciphers re all monoalphabetic ciphers.
INTRODUCTION TO
THE CIPHER:
The Bifid Cipher essentially takes a
Polybius Square Cipher to the next level of encryption. If you are not familiar
with the Polybius Square cipher, please visit my recent cache,
GCAXDB3
which introduces you to the Polybius Square
Cipher. Going forward with this cache, I will assume you are familiar with how
the Polybius Square Cipher works and thus will not go into detail on its inner
workings. Think of the Bifid Cipher as a second layer of encryption beyond what
the Polybius Square Cipher does. For my example, we will use the Polybius Square
below:
Lets take the word
"micro".
Now we know that a Polybius Square Cipher would convert
"micro"
into the ciphertext
3224134234.
The Bifid Cipher adds an additional layer
of encryption in three steps. Lets start with the first step:
MICRO
32143
24324
In the first step, we
took the two digit numbers for each letter in
"Micro"
from the Polybius Square above and wrote
them vertically not
horizontally under
each letter the numbers represent.
For the
second
step we will do the following:
Take the numbers from
above and write them out
horizontally going from left to right
like this:
3214324324
OR break it down by two digit sequences like this:
32 14 32 43 24.
Now lets see the final
layer:
The final step takes the
series of numbers from second layer of step and runs it back through the
Polybius Square converting those numbers back into a series of ciphertext
letters which looks like this:
32 14 32 43 24
M D M
S I
Hopefully you can see
how the new ciphertext came about. Its actually pretty neat how works.
IDENTIFICATION:
The initial challenge with
all ciphers is trying to identify what type of cipher you are dealing with. You
can find clues in the cache name as well as in the text of the cache page.
With a Bifid Cipher, you will see a series of letters that will not make any
sense. It will essentially look like a random series of letters. Look for words
such as poly, square, or the use of bi or by in the title. This type of puzzle
cache will likely have a higher difficuly rating as well given the level of
encryption. Always read the cache page carefully for clues as to what you are
dealing with.
VARIATIONS:
As with most ciphers, there
will be variations to any cipher. You just want to be aware of that. With
a Bifid Cipher, the Polybius Square used in encryption could have the letters of
the alaphabet, the in reverse order where
the letter "A" is in the 55 position and the letter "Z" is in the 11 position.
Different alphabets can also be used such at the Greek alphabet. Another
variation of this cipher is when a key is used to reorder the alphabet within
the square with the letters being placed at the beginning and the remaining
letters of the alphabet following the key in alpha order. If a key is used,
definitely be on the look out for hidden text or odd spacing in the text which
could hide the key. IF any of this trickery is going on, a clue that this will
not be a garden variety Bifid Cipher will be a high difficulty rating. IF you
see that, you should expect some monkey business going on with either a key or
an odd arrangement of the letters in the square. There is also another
version of the Bifid called the Trifid. We will save that for another
installment of this series.
THE SOLVE:
You can solve this cipher
as well as many others using several online decryption sites such as dCodes Tool List,
Braingle, Boxentriq and Geocaching Tool Box to name a few. There are websites
that can even help you identify what type of
cipher you are dealing with such as the Multi Encoder Decoder site or the Multisolver by dennistreysa.
THIS CIPHER:
Before we get to the main
event, I do want to state that
THIS CACHE IS NOT AT THE LISTED
COORDINATES! Dont go there
unless you plan to tube down the Cedar River. This cipher will not have any
trickery. There will not be any reverse text, double ciphers, curve balls or any
other tricks that will trip you up.
The ciphertext, once diciphered,
will give you the geochecker code you need to get the final coordinates. If your ready, lets give this cipher
a go!
MLCLYPOP
You can validate your puzzle solution with
certitude.