Boy thinking with coloured light and code background

Operation Decode – Lockdown Edition

Mission Six: Code Words

Codes and ciphers are both used in cryptography. While ciphers are a set of instructions for changing one set of symbols into another (like converting letters into numbers, for example), codes work by using words that normally mean one thing to mean another.

Codes are relatively simple to use. As long as both sender and recipient know the meaning of the codewords, they can communicate easily. This generally requires the use of a codebook, which must be kept hidden, in which all the codewords are listed.

Activity 6:


Use the code words in the codebook to figure out which of the three meanings provided is the correct interpretation of the message below.

Remember, when trying to decode a coded message, WHERE and HOW the words are used within the message can be just as important as WHAT words are being used. This is known as context, and it lets spies send complex messages without needing a specific codeword for everything they are trying to say!

Coded Message: Red Riding Hood has lost her basket. Visit the woodcutter’s camp, bring biscuits. Wait for the woodcutter and his two friends, they have an axe. Foxglove.

Code Book

Axe = Help

Banana Bread = Osprey

Basket = Information, Supplies

Big Bad Wolf = Enemy Operative/Agent

Biscuits = Raven

Bluebell = Be careful

Bring = Password is

Candy = Crow

Chocolate = Eagle

Coat = Cover, Identity

Daffodil = Flee immediately

Donuts = Condor

Ears are Keen = Our communications are being monitored

Eyes are wide = looking for you

Foxglove = Proceed quickly

Gingerbread = Falcon

Grandma = Central Command

Grandma’s House = Safehouse

Muffins = Buzzard

Porridge = Vulture

Raisins = Hawk

Red Riding Hood = Operative, You

Shoes = Transport/Vehicle

Snowdrop = Go to ground, Remain hidden

Teeth are sharp = Actively pursuing

Wolf’s Lair = Enemy Base

Woodcutter = Friendly Operative/Agent

Woodcutter’s Camp = Meeting Point

Woods = Hostile/Enemy held territory

Pathway = Public areas

Strengths and Weaknesses


  • Can be used to securely communicate sensitive information even over non-secure channels
  • Single words can be used to represent complex instructions or messages


  • Complicated code systems require the use of a code book
  • Security of the code is entirely dependent on the security of the code book. If the code book is captured, the code becomes useless