As a result of their solutions to this puzzle, store owner Jeremy promoted both Cerberus and Quark to top managerial positions.

Soon after starting their new roles, they were somewhat surprised when they noticed gorgeous women visiting Jeremy privately in his office each week, unbeknownst to his wife. Then, one day at a lunch meeting with his 2 new managers, Jeremy said that he trusted them, and revealed that he "secretly" had a couple of girlfriends, and that he has also created his own simple encryption method to protect the short emails that he sends to them, contrary to the "Don't roll your own" advice of the smart folks at Information Security.SE. He has also given the women a simple decryption program so they can communicate with him.

Before the multiple-lover/adultery information could even sink in, Jeremy offered them another challenge. The first of them to figure out his simple email encryption algorithm would be promoted to region manager, which would include a fat raise over their already-large recent increase. He provided them with a very short plaintext email, along with the associated ciphertext and a couple of hints, and wished them luck.

Hint #1:
Jeremy: You solved my Master lock challenge, and you know that I am not that creative, just clever.

Hint #2:
Jeremy: Using my algorithm, the same message can be encrypted to many different ciphertexts.

Email plaintext:

Email ciphertext:

Can you figure out Jeremy's encryption algorithm before his managers do?


1 Answer 1


I think I got it.

As it is easy to see, every word is a letter from the plaintext
and so on

Taking a look at the puzzle from the first hint, and the information about the lack of creativity. I played a bit with the spacing between the letters:

PARROT = 15 0 17 17 14 19
15 (|15-0|) 17 (|0-17|) 0 (|17-17|) 3 (|17-14|) 5 (|14-19|)
doing the same thing over and over again until we have only one letter left
15 17 0 3 5 => 2 17 3 2 => 15 14 1 => 1 13 => 12 which coresponds to M

NECTAR = 13 4 2 19 0 17
13 4 2 19 0 17 => 9 2 17 19 17 => 7 15 2 2 => 8 13 0 => 5 13 => 8 = I

GABBY = 6 0 1 1 24
6 0 1 1 24 => 6 1 0 23 => 5 1 23 => 4 22 => 18 = S

And so on. Sorry for not putting all the words here, but I am posting this in the lunch break and I am running out of time. If needed, I will post all of them when I get home. :)

The second hint refers to the fact that there are many words that will end up with the same value. I don't have an example now, but I think that I can come up with some sort of script that will provide words for a given letter.

  • 2
    $\begingroup$ Bravo! Good answer. $\endgroup$
    – CodeNewbie
    Commented Jul 30, 2015 at 9:57
  • $\begingroup$ Absolutely excellent! After this puzzle got few upvotes and little attention, I figured that I'd soon need to incorporate more clues, but to my surprise, it's solved as is! I am so impressed that I am going to give you 200 rep points on top of the 10 + 15 that I would normally give an accepted answer (in 5 hours when this question is eligible for a bounty). $\endgroup$
    – JLee
    Commented Jul 30, 2015 at 14:30
  • 1
    $\begingroup$ @JLee, I really appreciate that. I consider myself very lucky that I had the chance to see this puzzle and play with it before others (I am sure that if it were not for my lunch break, someone would have figure this thing out...there are a lot of sharp, smart guys around here). Plus, I got to learn a new word: unbeknownst :) $\endgroup$ Commented Jul 30, 2015 at 14:50
  • $\begingroup$ I just read my previous comment. All I have to say is: Bad grammar, bad grammar everywhere... $\endgroup$ Commented Jul 30, 2015 at 15:03

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