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We Spies Live by a Code…

Greetings agents, it’s your old pal Cluck here. It’s not easy going undercover as a chicken. People keep getting you to cross the road then ask, “Why?”

This week we are looking at one of the tools of the covert agent—the coded message. When you have top secret information, you sometimes need to pass it on in a way that the bad guys can’t read. That’s where codes and ciphers come in.

A code is a way of changing information from one form to another, usually shortening it to make it easier to transmit. Jpg, mp3 and mp4 files are all ways to encode information in a smaller package to make it easier to send.

Here’s a simpler example, if I want to send you the message: “I would like a grilled cheese sandwich on white bread with a glass of milk and extra pickles,” that’s a lot of letters to type, especially if you’re a chicken. If you and I agree that the code word “Plop” means the same as the big cheese sandwich sentence, then we can send the same information with a lot fewer letters. If you have a whole bunch of code words that have different meanings, you can record them in a Code Book.

Codes are not usually designed to conceal information but both people in the conversation have to know what the words mean in order for it to make sense. 

A cipher scrambles the letters that make up the words of the message to hide what it means. One of the earliest examples is the Caesar Cipher that Julius Caesar used for his private messages. Each letter of the message is shifted forward a certain number of letters in the alphabet.  

In this case,  A becomes S, B becomes T,… and Z becomes R

So “PICKLE” would become:

P = H
I = A
C = U
K = C
L = D
E = W

“PICKLE” =  “HAUCDW”

The code wheel we looked at last week uses a variation of the Alberti Cipher which replaces each letter in the plain message for a cipher letter that appears to be in a totally random order. Sender and Receiver both need the same code wheel or they will not be able to communicate.

Until next week Agents...“Plop” (and don’t skimp on the HAUCDW’s) 

This week’s secret message:

(Deciper this way: A becomes R, B becomes S, C becomes T...Z becomes Q, etc.)

Why did Cluckminster cross the road?

CX PNC CX CQN XCQNA BYH


Share your own Spy Jokes with Cluckminster at cluckminster@scienceworld.ca
 

Check out Cluckminster's last blog entry.

Your mission: Top Secret: License To Spy, should you choose to accept it, is on now at TELUS World of Science.