So yesterday on the bus ride back from school I was sitting beside my friend James talking about food (we were really hungry from all the still life paintings in Art class). Suddenly, his gaze wandered away and he stopped talking. I was getting used to this - lately James had took up a new hobby, cryptography, and sometimes had "brilliant puzzle ideas" he liked to share with me. I sat silently for a minute or so until he got down the bus and said simply "Tell you 'bout it tomorrow". "Sure", I said, "See you tomorrow".

The next day, as I entered the classroom, he handed me a scribbled piece of paper:

Today at breakfast the weirdest thing happened. I was eating something tasty, when all of a sudden a witch popped up right in front of me! She cracked a laugh and said:

"Behold, I am the Breakfast Witch, computer age vegan activist.

For you crimes against nature you shall pay! But fear not, child, your skin I shall not flay.

A curse upon your breakfast is enough - so you may never taste this stuff.

There is even a way to lift it, in fact; there has to be, per the Witch Contract.

Your evil treats I shall transform into twelve five-element magic forms,

And upon that another layer of deception shall further obscure the information.

But in the case you can see beyond the lies, I shall restore your murderous meal to its original guise"

The Breakfast Witch disappeared, and I instantly forgot what I was eating. I couldn't tell for the life of me what I was having for breakfast! Instead, what I saw in my plate, smelled in the air and tasted in my mouth was (don't ask me how!) "218D103061009AC". What was I eating?

I had no clue at all how to solve that. To me it looked like a crazy riddle and an even crazier sequence of letters and numbers! During break I went online and searched for the numbers, but found nothing. James kept asking me every chance he got if I'd "figured it out yet". So annoying.

By the end of the day, I was still stumped. I really want to crack this, if just to put an end to the smug way James keeps smiling at me. Searching online at home I found this site and figured it would be a great place to solve this and finally put an end to at least this one puzzle. So, can you help me find out what he was having for breakfast?


1 Answer 1


The answer is:


Let's start from the end. Combination of digits and letters looks like a hex number. Let's try converting them... If we convert it to binary, we get 60 (which is 12*5) digits (leading zeros appear from digit-by-digit conversion). This looks good, as it suits for "twelve five-element magic forms" and conversion to hex is "another layer of deception"

00100 00110 00110 10001 00000 01100 00011 00001 00000 00010 01101 01100

The Breakfast Witch indicated "another layer of deception", which we remove by the transformation $0\to A$ and $1\to B$:


This is the Baconian Cipher, which finally yields


And that's what James was having for breakfast.

  • 4
    $\begingroup$ That's the Bacon cipher, which has a version that merges the letters I and J (when it was invented, I and J weren't considered entirely separate letters). That effectively decreases the numbers for the letters after J by 1. $\endgroup$
    – f''
    Commented Oct 19, 2015 at 17:39
  • 1
    $\begingroup$ "I" shall restore you ... The alphabet is missing I, so 17 is S, 12 is M, etc... (Oops, ninja'd) $\endgroup$ Commented Oct 19, 2015 at 17:46
  • $\begingroup$ That's it! I was going by this image. As my first attempt at a puzzle, I'd like to ask: was it too easy? $\endgroup$
    – Gabriel G
    Commented Oct 19, 2015 at 18:03
  • $\begingroup$ It was pretty easy, but not too easy, I think. At least you need to know about Baconian Cipher :). $\endgroup$
    – Alissa
    Commented Oct 20, 2015 at 9:04

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