The Code

Decrypting a Mural

The high school I attended was a small magnet school with a strong academic focus, to the extent that there were no sports club with the exception of the informal “Winter Running Club”. As standard for most high schools, the walls were adorned with murals and selected student work. One of the more memorable ones was a cryptic painting titled “The Code”.

As I was looking through my old photos, I stumbled across this photo and realized that I never got around to figuring out what it meant. I called up an old friend, Kenny, so that we could work on it together. The only non-hidden information was “Kryptos”¹ written counterclockwise around the outside and “Decrypthis!” at the start of the table of letters. We started by transcribing the table, since the calligraphy was a bit hard to read for some letters.

Morse Code

The first step was translating the morse code around the outside, to which we got the message “HMNESTKA/A/A” which didn’t seem right all, even after trying to unscramble the letters. Looking back at the painting again, we noticed that some of the dashes seemed too long, so we translated again counting them as 2 dashes, getting us the message “HONESTYA/A/A”. After some additional searching, I discovered that A/A/A translates to a full stop if there are no spaces,² meaning that “HONESTY.” was the final result of the morse code.

Searching for a Cipher

At this point, we had 3 short keywords (“Kryptos”, “DECRYPTHIS!”, and “HONESTY.") and a message to decrypt. We tried out a variety of ciphers and read through several decrepit webpages to try to find information about graphical ciphers or cryptography in general, since neither of us were too familiar with the topic.

As I was messing around with an online Vigenère cipher, I found that inserting a word such as “ROOT” into the keymaker produced the key “ROTABC…”. Of course! Since the purpose of the keyword was to scramble the alphabet, a duplicate character has no effect. I plugged in “DECRYPTHIS” as the keyword and “HONESTY” as the passphrase, which got me english text with some minor transcription errors on my part. After fixing those and adding in punctuation, the final message was a quote from the former Dean of Vanderbilt University:

Today I am going to give you two examinations, one in trigonometry and one in honesty. I hope you will pass both, but if you must fail one, let it be trigonometry. — Madison Sarratt³

The main message was decrypted.

Polynomial

If the numbers around the outside are treated as an equation, the polynomial can be solved to x = 2, 5, 7, 8, 10, 12, 15 which seemed too perfect for coincidence. After various manipulations with these roots, Kenny noticed that the equation started with “8 = …” which may represent that y = 8. Putting that together with the x-y axes in the painting, we got the letters at the coordinates specified, which yielded “EYTHSⓄN”. After some descrambling, we get the “HⓄNESTY” keyword again, perhaps as an alternative way to solve the main cipher.

Tying Up Loose Ends

Because of the x-y axes and the extraneous punctuation, we assumed that there would be another layer of encryption such that 2 long messages could be extracted from the main table. However, given that we exhausted most of the clues, there is probably no second layer since there isn’t enough information given. The other mystery is the compass, which we eventually chalked up to a reference to the assumed inspiration of the puzzle.⁴

It was quite fun decrypting this code, because I will never forget the feeling of accomplishment from extracting english text after hours of borderline conspiracy theories about what each part of the message could mean, ranging from the black streak on the East and North-East spokes of the compass to the meaning of the capital K in Kryptos. It gave me a newfound interest in cryptography and puzzle solving.