4. Null Ciphers

OLD EPISODE
In this episode, we talk about Null Cipher, a type of cipher unknown to many, with Caw the Crow, a new spy, and Codemaster Cole. Null Cipher, an interesting and easily changed cipher, as well as one that can easily be combined with other codes. Also, hear a story about how a Null Cipher saved a life, and a list of Null Ciphers to try. Could you please subscribe to the show on Spotify or Apple Podcasts?

After this episode, we'll be taking a week off for christmas, but after that we'll have a much longer episode, so stay tuned.

The background music used in this episode are Bio Unit, 4 AM, Mainframe, and Apex, all by Bio Unit, and our theme song is Mosquito by Caspar Babypants.

 You can find Dr. Gareth's work at drgarethmoore.com. He has released many puzzle and cipher related books for kids, as well as a lot of stuff for adults, too. 

Chapters

• 0:00 Theme Music
• 1:42 Intro
• 2:58 The Key to Null Cipher
• 5:14 Magazine Null Cipher
• 6:05 History Story: The Cipher That Saved A Life
• 8:06 Story
• 13:22 Null Cipher Examples
• 15:10 Outro

Transcript

Barnabas  01:43
Welcome to the Kids' Code Podcast. I'm Barnabas, your host, and today we will be talking about Null Ciphers with Caw the Crow, the newest member of the good spy ring, and Codemaster Cole. Null Ciphers, though you may have never heard the name, are one of the most used codes. A null cipher is a concealment tactic in which only certain letters in a message mean anything - like the second letter of every word. The other letters are called Nulls - that's how Null Ciphers got it's name. For an example, if you look closely at the code wheel in our cover art you will see that every other letter on the outer wheel spells out "with Cobra". Cobra is my codename*. Codemaster Cole, it's your turn to give an example of a Null Cipher.

Codemaster Cole  02:59
I'll give you a list of words that seem random, but are really a null cipher message. You can pause the episode after I've said them to try to figure out what the secret message is. When you turn it on again I will give you the answer. Here is the message:
Stone Average Vine Eat Your Octagon Use Regular Side End Let From.
Are you ready? Did you figure out the message? It's OK if you didn't because here is the answer. If you only read the first letter of each word the text says SAVE YOURSELF. Now, this message is likely to arouse suspicion, since it is just a jumble of words. For more important messages you'll want something that makes more sense like this example from Top Secret: SOME ANTIQUE VASES EASILY YELLOW. OTHERS USUALLY RESIST. SOME ENAMELS LAST FOREVER. The more hidden a message is, the less likely it is that it will be found by the enemy.

Barnabas  04:56
Of course, there are other Null Ciphers. You could use the last letter of every word. Or the first letter of every 4th word. You could hide entire words, too - such as the third word of each sentence. Here is another kind of Null Cipher. It's easier to crack, but I still think you'll like it. In England, at a time when it was expensive to send a letter, but newspapers could be delivered for free, many people would send their personal "letters" by punching pinholes or writing small dots under the letters that were in their message. You could use this technique as a code, too. In a magazine or newspaper, mark the letters of your message with a small dot. You can make a system in which the message is in a different section or on a different page on each day of the week. This is the story of how a Null Cipher that saved a life.
In the 1600s, during England's Civil War, the Puritans captured Sir John Trevanian, a Royalist. They imprisoned him in a castle in Colechester, a city relatively near London. He would have been killed if he didn't escape. Then Sir John got a letter from a friend. His jailers didn't find anything suspicious in the letter, so they gave it to the prisoner. Sir John, however, was immediately releaved because he knew that there was a secret message hidden in the letter. If you only read the 3rd letter after each punctuation - the system Sir John and his friends used - it would say "panel at east end of chapel slides". Just as no one questioned the letter that Sir John recieved, no one questioned his request to spend time praying in the chapel soon after he got the letter. An hour later, his jailer came back to check on the prisoner, but Sir John had been gone for a while.

Caw the Crow  07:39
That was a cool story.

Barnabas  07:41
And it just goes to show that, like Codemaster Cole said earlier, the more concealed a code is, the less suspicious it will be.

Codemaster Cole  07:57
Now can we finally find out what happens at the museum?

Barnabas  08:04
It's time for the story, so yes.

Barnabas  08:11
The good guys (particularly Fred Fine, Police Chief Al, Steve, Dan, Caw the Crow, Great Greg [who is Caw the Crow's partner], and Codemaster Cole) were getting ready to sneak into the museum so that they could catch the badguys.

Codemaster Cole  08:40
Hey everyone, we've got to go very quietly and carefully into (and in) the museum.

Barnabas  08:54
Said Codemaster Cole.

Caw the Crow  08:59
Okay.

Barnabas  09:01
Said Caw the Crow. They snuck in and started waiting for the badguys to arrive. While most of them listened for sounds, Great Greg and Fred Fine looked at the interesting paintings.

Fred Fine  09:32
Oh, that's a really cool painting.

Barnabas  09:38
Said Fred  Fine to Great Greg. During this time, the badguys were coming in.

Dangerous Dave  09:54
Sneak in quickly and quietly.

Barnabas  09:59
said Dangerous Dave. They did, and they were getting ready to do stuff, when all of a sudden, Horrible Hal said

Horrible Hal  10:14
Hey! I heard something.

Barnabas  10:21
Immediately after which, Steve said

Steve  10:26
I heard something.

Barnabas  10:30
Then, Dangerous Dave started listening, and said

Dangerous Dave  10:36
It's only the echo of your own voice.

Horrible Hal  10:40
Maybe, but I think it's more than that.

Barnabas  10:44
Said Horrible Hal. Then, the badguys went to a safe where the treasure not being used in current museum exhibits was kept.

Horrible Hal  10:59
Hmm. There seems to be a code that we have to solve.

Barnabas  11:10
Said Horrible Hal.

Dangerous Dave  11:15
It looks like Null Cipher.

Barnabas  11:18
Said Dangerous Dave. Dangerous Dave, The Evil Ant, Horrible Hal, Terrible Tim, and all the other members of the bad spy ring** started working on the coded lock while the good guys came closer. Then, when the thieves were about to figure out the message, the good guys jumped out of hiding and Police Chief Al and Fred Fine arrested the badguys. Then, the police officers said that they would take the the thieves to jail. During this time, Dangerous Dave and the evil Ant moved away from the good guys, jumped, and ran away. Steve and Dan saw them escape.

Steve  12:34
They're escaping!

Barnabas  12:36
Called Steve. Then, all all the goodguys went after them, but Dangerous Dave and the Evil Ant were to quick, and they had gone to far to follow.

Codemaster Cole  12:54
You'd better catch them.

Barnabas  12:57
Said Codemaster Cole to Steve and Dan. THE END.

Barnabas  13:10
Well, I hope you like the story. I guess next time we'll have to follow the Evil Ant to find out what he's up to. If you want to experiment with Null Ciphers, here is a list of ones to try. 

• First letter of each word. 
• Last letter of each word. 
• Middle letter of each word. 
• Every 7th letter. 
• 5th letter after each punctuation mark. 
• Last letter of every 5th word. 
• First letter of every 3rd word. 
• Fourth word of every sentence. 
• Every 6th word. 
• Every 10th word. 
• 2nd letter after every "e". 
• 9th letter of every appearance of the word "a". 
• 3rd  letter of every appearance of the word "the". 

In a couple of these ciphers, there might be places that, for example, don't have a middle letter. That's fine. Just skip to the next word or sentence.

Barnabas  14:32
I think Null ciphers are very cool.

Codemaster Cole  14:37
Me too.

Caw the Crow  14:40
Me 5157.

Codemaster Cole  14:46
Wait - didn't they already make that joke in episode 2?

Caw the Crow  14:53
Yeah, but I want to tell it too.

Barnabas  14:58
I don't think that it's very funny the second time.

Caw the Crow  15:04
I don't care very much. I just want to tell a joke.

Barnabas  15:11
That's it for today. Next time we will talk about how to break some of the codes we've learned. My sources for this episode are Top Secret by Paul B. Janeczko and The Spy's Guidebook by Falcon Travis, Judy Hindley, and others. See you next time!

*Codenames - we might talk about codenames in a later episode.
**Not counting Emily End.