Month: January 2018

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.