Challenge 16: Hollow Pursuits

I’m woefully behind on posting my weekly puzzles, so I decided to play catch-up by posting as many as I can churn out in one week. Here’s Challenge #16 for January 14, 2018.

This cipher has a picture clue!

This image should give you two pieces of information: the cipher type and the key. Each can be attained by chasing down a different piece of history related to the Jefferson Nickel: for the cipher type, a mystery; for the key, an origin story.

Additional hints:

  1. Notice anything strange in the image?
  2. ET AON RISBCDFGHJKLMPQUVWXYZ
  3. The key is a person’s last name.
  4. The key in letters is 6 characters long. Once converted to numbers, it is 10 digits long.

Here’s the ciphertext. Good luck!

04626 96622 85647 35144 54308 36773 34454 49946 78139 97502 15140 54629 33318 40343 94106 38047 29352 60205 71207 00141 92727 02741 77363 79574 84881 53547 03375 19693 27344 36506 75347 16025 17167 59376 86687 47375 24945 21945 58548 50142 13828 3677


With CodeAWeek.com, I hope to release one cipher, puzzle, or mystery each week. Anyone can attempt to solve. The winner is the first person to send a correct solution and a description of the solve method to codemaster@codeaweek.com. Once a correct solution is e-mailed, I will publish a follow-up post, congratulating the winner and revealing the secrets of the code.

You may post questions or theories in the comments, but DO NOT POST SOLUTIONS. E-mail them to codemaster@codeaweek.com.

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Challenge 15: June 1918

Here’s Challenge #15 for January 13, 2018.

The year is 1918. You’re a cryptanalyst working for the Allies, and you’ve just intercepted this German Morse-code communication.

--. ..-. -..- --. ..-. .- -.. -..- .- -.. ..-. .- .- -..- / --. .- --. --. --. -.. --. --. -..- -..- --. -.. -..- ..-. / -..- ..-. .- ..-. .- -..- .- -.. --. --. --. .- ..-. -..- / .- -..- --. -.. .- -..- .- -.. -.. -.. .- -..- --. ..-. / .- -..- ..-. -.. .- .- -.. --. ..-. .- .- -.. -..- ..-.

Can you figure out the message and save lives?

Here are some hints:

1. You need to translate these dots and dashes into letters.
2. Is there anything unique about the resulting letters?
3. Who was the first to break this type of cipher?*
4. You’ll need 2 keywords: One for a mixed alphabet and one for a transposition.
5. Before entering the keywords, delete repeat occurrences of any letters. (Ex. NEBEL would convert to NEBL.)
6. I=J
7. The plaintext is in English, not German.

* For purposes of simplicity, this cipher type is an earlier version of the type he cracked. If you are familiar with the two types, it’ll be obvious which it is based on the ciphertext letters. 

With CodeAWeek.com, I hope to release one cipher, puzzle, or mystery each week. Anyone can attempt to solve. The winner is the first person to send a correct solution and a description of the solve method to codemaster@codeaweek.com. Once a correct solution is e-mailed, I will publish a follow-up post, congratulating the winner and revealing the secrets of the code.

You may post questions or theories in the comments, but DO NOT POST SOLUTIONS. E-mail them to codemaster@codeaweek.com.

SOLUTION to Challenge 3: A Simple Calculation

Congratulations to Euchre Mutt for being the first person to solve Challenge 3!  The puzzle remained unsolved for a whopping 134 days … a site record! … which means he is awarded 134 points on the Leaderboard.

If you haven’t tried your hand at solving it, read this first.

Here’s original description and ciphertext:

With this cipher, I hope to add a new encryption method to the playbook. If you formulate the correct hypothesis, you just might take away the prize.

Some clues:

  1. It’s a substitution cipher.
  2. The ciphertext is 102 characters. The plaintext solution is 34 characters.
  3. What is 102 divided by 34, and what does that tell you?
  4. The plaintext solution is a quote from a famous mathematician.

The ciphertext is:

LCFBPDLED HCJJKAHFF TSNIGANRK GMBHJMQCO XETSSRVLZ CFDZOWVLP JJKFSRPCK BXFIVPWJO RSLYNXFSD HRHAOKQQK IJAEPFBUI QPZ


The key to solving this cipher lies in a very simple mathematical formula. It’s so simple that you’re going to kick yourself for not figuring out.

First, number the alphabet, where A=1, B=2, C=3, etc.

Now, space the ciphertext into blocks of 3 characters and apply the following formula to each block: A+B-C

The result of that formula is one plaintext character. Apply the same formula to every block of three characters, and you’ll discover the solution.

For example, if we apply it to the first three characters “LCF” …

L+C-F=

12+3-6=9

9=I

Continue down the line to get the solution:

“In math, you’re either right or you’re wrong”

… which is a quote by NASA mathematician Katherine Johnson. Johnson was profiled in the book and film Hidden Figures.

There are a couple of hints in the challenge description, which I’ll put in bold here:

With this cipher, I hope to add a new encryption method to the playbook. If you formulate the correct hypothesis, you just might take away the prize.


With CodeAWeek.com, I hope to release one cipher, puzzle, or mystery each week. Anyone can attempt to solve. The winner is the first person to send a correct solution and a description of the solve method to codemaster@codeaweek.com. Once a correct solution is e-mailed, I will publish a follow-up post, congratulating the winner and revealing the secrets of the code.

You may post questions or theories in the comments, but DO NOT POST SOLUTIONS. E-mail them to codemaster@codeaweek.com.

SOLUTION to Challenge 13: Fractionating

Congratulations to Euchre Mutt for being the first person to solve Challenge 13!  It remained unsolved for 45 days, which means he is awarded 45 points on the leaderboard.

If you haven’t tried your hand at solving it, read this first.

Here’s original description and ciphertext:

Today, I wanted to learn about ciphers that use fractionation. I decided on a method created by a French amateur cryptographer who spent his days in working in a customs warehouse.

Three hints:

  1. J=I
  2. You need to figure out the keyword and the period.
  3. “Now Morn her rosie steps in th’ Eastern Clime, Advancing, sow’d the earth with Orient Pearle.”

And the ciphertext is:

xmwuv hnmhv hderq
tbkht newsv hnmhv
fpeks ngifq rlqv


The solution:

This puzzle uses the bifid cipher, invented by Félix Delastelle around 1901. Delastelle was a bonded warehouseman by day and an amateur cryptographer by night. The bifid cipher uses a numbered grid in a very clever way to fractionate the plaintext, making it harder to crack.

The third clue is a line from Milton’s Paradise Lost.  That should help you figure out that the keyword is MILTON. Incidentally, this is the opening line from Book 5, which should lead you to a block length of 5.

The decoded text reads:  “Who overcomes by force, hath overcome but half his foe, ” another quote from Paradise Lost.

You can use this online Biphid Decoder to test all this out.


With CodeAWeek.com, I hope to release one cipher, puzzle, or mystery each week. Anyone can attempt to solve. The winner is the first person to send a correct solution and a description of the solve method to codemaster@codeaweek.com. Once a correct solution is e-mailed, I will publish a follow-up post, congratulating the winner and revealing the secrets of the code.

You may post questions or theories in the comments, but DO NOT POST SOLUTIONS. E-mail them to codemaster@codeaweek.com.

SOLUTION to Challenge 11: The Right Type

Congratulations to Puzzling.Stackexchange user Kayzeroshort for being the first to solve Challenge 11! It took him 12 days, which means he is awarded 12 points on the Leaderboard.

I’ll reveal the secrets below, but if you haven’t tried your hand, read this first.

The ciphertext:

YGWCSD QDCHVF WCLEZJ CHCTJQ YUEOYG YSE,GY KYJXDZ KYCYEP IFKWGW
TIHOEP CHRTJR DOCRTU YGY,HB PEDWUC GWU.QD ;WRTDR BESDOY ZDMNUC
SFQDCH RKWCH. POXHQO QFYOY. YPSAYR QFYHYG Y,HGIT YGRT

The original post:

Today’s cipher is a method I created based on a known method, although it is likely that someone else thought of it before me.

I’ll give you three clues:

    1. The method is a spinoff of the famous method used to encode Challenge 10.

    2. The punctuation in the ciphertext encodes letters in the plaintext. (There is no punctuation in the solution.)

    3. The following text is not a deciphering tool but a clue that will point you in the right direction. What came after this?

      3 5 7 9 N O P Q R S T U V W X Y Z
      2 4 6 8 . A B C D E F G H I J K L M

The solution, as explained* by kayzeroshort on Puzzling.Stackexchange:

The lines …

3 5 7 9 N O P Q R S T U V W X Y Z

2 4 6 8 . A B C D E F G H I J K L M

… are the characters used on an early typewriter designed by Christopher Latham Sholes. He went on to invent the first typewriter with a QWERTY keyboard layout, the same layout used on modern day computer keyboards.

That clue leads to  your own computer keyboard being the codebook. Using your keyboard, you can follow the rules of the Playfair cipher to decipher the code. The grid would look like this:

QWERTYUIOP
ASDFGHJKL;
ZXCVBNM,./

The deciphered text is

T H E X A S E A N D F R E X D O M A N D B E A U T Y W I T H W H I C H T H I S M A C H I N E W O R K S I S T R U L Y W O N D E R F U L E V E R Y T H I N G N O W S E E M S T O M E A S P E R F E C T A S I T C A N B E M A D E A N D I F E X L N O I N S P I R A T I O N T O A ; T E R A N Y T H I N G F U R T H E R

or

THE EASE AND FREEDOM AND BEAUTY WITH WHICH THIS MACHINE WORKS IS TRULY WONDERFUL. EVERYTHING NOW SEEMS TO ME AS PERFECT AS IT CAN BE MADE AND I FEEL NO INSPIRATION TO ALTER ANYTHING FURTHER.

As with the Playfair cipher, to get the final deciphered text from the raw decipher, replace X’s with the previous letter.

The plaintext is an excerpt from an 1870 letter by Christopher Latham Sholes about his new typewriter. It was some of the first text ever written on the QWERTY typewriter.

The puzzle title THE RIGHT TYPE is a hint alluding to “typewriter.”

* lightly edited by me.

 


With CodeAWeek.com, I hope to release one cipher, puzzle, or mystery every week. Anyone can attempt to solve. The winner is the first person to send a correct solution and a description of the solve method to codemaster@codeaweek.com. Once a correct solution is e-mailed, I will publish a follow-up post, congratulating the winner and revealing the secrets of the code.

You may post questions or theories in the comments, but DO NOT POST SOLUTIONS. E-mail them to codemaster@codeaweek.com.

SOLUTION to Challenge 10: No Cheating

Congratulations to Stackexchange user M Oehm, who was the first to solve NO CHEATING. It took him one day, which means he is awarded 1 point on the Leaderboard.

I’ll reveal the secrets below, but if you haven’t tried your hand, read this first.

The ciphertext:

WXYCNW LAHWNZ WONSNI LEXAPE OSMWOW RCSRQC AZ

And the original puzzle description:

Today’s cipher is a famous cryptographic method known for its economy, ingenuity, and difficulty in cracking. Its inventor created all sorts of cool things, including musical instruments, a timepiece especially useful at the North Pole, and the earliest ancestor of the Oculus Rift. Aside from this cipher, which does not bear his name, he is most famous for co-inventing a means of communicating at long distances.

The key to unlocking the mystery is his name. Good luck!

The solution:

The title “NO CHEATING” was meant to lead you to the Playfair cipher, created by Charles Wheatstone in 1854. He invented all sorts of cool things, including the English Concertina, the Polar Clock, the Stereoscope. He co-invented telegraphy, a means of communicating at long distances.

The key is CHARLESWHEATSTONE. You make a 5 by 5 square and fill it with the letters of the alphabet, starting with the key.  This gives the following square:

C H A R L
E S W T O
N B D F G
I K M P Q
U V X Y Z

Since our square only has 25 spaces, we must do away with one letter. In this case, that letter was J.

We follow the rules of the Playfair Cipher to get the message:

AM UR DE RH AS GU ST BE EN CO MX IT TE DA TS AL TH IL LX

If we take out the padded Xs and convert the G* to a J, we get the fully decoded message:

“A murder has just been committed at Salt Hill.”

… which is the first line of an early telegraph that helped catch a murderer. It was the first arrest ever made using the technology.

* Usually J is encoded is I, but I made a mistake and coded it as G here.


With CodeAWeek.com, I hope to release one cipher, puzzle, or mystery every week. Anyone can attempt to solve. The winner is the first person to send a correct solution and a description of the solve method to codemaster@codeaweek.com. Once a correct solution is e-mailed, I will publish a follow-up post, congratulating the winner and revealing the secrets of the code.

You may post questions or theories in the comments, but DO NOT POST SOLUTIONS. E-mail them to codemaster@codeaweek.com.

Challenge 14: What Futility

Here’s Challenge #14 for December 5, 2017.

Perhaps nothing really matters, but don’t give up hope on this cipher. The method was first used by a political group in the late 1800s to organize terrorism against a regime.

Here’s the ciphertext:

35567034476476485766664594664748705756684736670957649465665776352458564548986557663558749844657733573488382658733566873446583445577738269437474486344658663936896644865435579738476474575780564754567565096456543367648945287773756689444577435834707447854565489865576635395407572476335738703428564358340957349555584888574666443944983437583745467654647645656476662467374744867728545539367057345455587478345685745757805647946478747064456763676686484756473664783428943357387936367743676770363654377546765436946658367074248673676570344677433875884624666467440634268634754767744764377574075636545436348964475476

Hints:

  1. No J.
  2. There is a keyword, and there is a key. Both are last names. One is a real person. The other is a fictional character.
  3. How well do you know your classic Russian literature? I’m thinking of a particular book that popularized a term used in the cipher type’s name.

With CodeAWeek.com, I hope to release one cipher, puzzle, or mystery each week. Anyone can attempt to solve. The winner is the first person to send a correct solution and a description of the solve method to codemaster@codeaweek.com. Once a correct solution is e-mailed, I will publish a follow-up post, congratulating the winner and revealing the secrets of the code.

You may post questions or theories in the comments, but DO NOT POST SOLUTIONS. E-mail them to codemaster@codeaweek.com.