Let’s mix up the Code Column for this edition and go big. Look out mobile users! This is a step up from the more basic substitution ciphers we’ve looked at over the past year.
Blaise de Vigenère developed this table (or square) using alternate alphabets to create coordinates for shifting letters into a code, one which needed insider knowledge to decipher (without great effort anyway).
Putting codes on the table
To play with this cipher we need three things:
Firstly, a Message. This is the really important stuff. In fact, let’s use that.
REALLY IMPORTANT STUFF
Old mate Blaise was also one of the first code-fiends to come up with one of our favourite things – a secret Key! So that’s our second piece:
ESCAPE
Then we go to our big fun Table, with the SIDE letters for our MESSAGE, and the letters along the TOP for our KEYWORD. These give us ‘grid references’ on the TABLE for our ENCODED TEXT.
Squaring things up
We need to get our Message and repeat our Keyword until it is all ‘covered’. (I’ve broken it into groups of five for easier reading).
ESCAP EESCA PEESC APEES
REALL YIMPO RTANT STUFF
So our first Message letter ‘R’ has the Key ‘E’. Find ‘E’ in the Top row, then follow this column down until level with our Side reference ‘R’. This gives us ‘V’!
Using the same process from ‘S’ to ‘E’ gets ‘W’.
On and on, and we get a nonsense CIPHERTEXT that we can send to a friend.
VWCLA CMERO GXEFV SIYJX
Turn the tables
The recipient needs to know the Keyword to be able to decode this Ciphertext. If you don’t have the Keyword, you’re going to need way more than your scheduled hour to break this. But your Escape Room should have the keyword there to be found (keep searching!).
So you have found a Ciphertext (our apparent gibberish) and a Keyword in your Escape Room, now you need to use the Table to find the Message.
QQDRPMRZCRIW
Working to decode this, we write out our Keyword once more to ‘cover’ – but this time on top of the Cyphertext.
E SCAP EE SCA PE
QQDRP MRZWR IW
Working backwards from before, we find ‘E’ on the Top/Key, and go down its column until we find ‘Q’ on the grid, trace across to the Side and hey presto- it’s ‘M’!
Next we follow ‘S’ on the Top down also to ‘Q’, and we get ‘Y’. You can handle the rest!
Flip the Table!
Make this one harder to crack by having a longer Keyword(/s) or mess around with the letter placement on your Table. Just make sure the person you want to decode it is working from the same Table as you are. The Vigenère Cipher is valuable because its randomizing system works against Frequency Analysis (read about this in a future edition of ERA) in that you can’t just pick the most commonly reoccurring letters to be ‘E’.
Where to find this in an Escape Room?
This one may be on the rare side in Escape Rooms, and the grid itself is hard to disguise. Look for it in espionage-based rooms and you can use your practice today to decipher it in seconds, to the amazement of your team!
KGQD AYGC!
