Advanced Cipher Hunt

About 90 minutes, outside, for ages 11 and up.

Where it works

Works in any outdoor space

Who it's for

ages 11 and up

Ciphers To Try:

  • a message shifted by a number (Caesar cipher)
  • a message written backwards
  • a message using only the first letter of each word
  • a message swapped in pairs of letters

Today's Challenge

  1. 1.Which cipher was hardest to crack?
  2. 2.Which cipher was fastest to write?
  3. 3.Could you invent your own cipher?

Quick Start: What you need

  • 1notebook
  • 2pen

The Goal

A harder sequel to the classic code hunt using more than one kind of cipher.

How to start

  1. 1

    Gather what you need: notebook and pen. Nothing else required.

  2. 2

    Head outside and try: a message shifted by a number (Caesar cipher), a message written backwards, a message using only the first letter of each word, a message swapped in pairs of letters.

  3. 3

    Talk about what you made. Start with "Which cipher was hardest to crack?"

  4. 4

    Print the worksheet to plan it out and keep what you make.

Invent Your Own Cipher

Design a brand new code system below, then explain the rule so someone else could learn it.

During World War II, the U.S. Marines used Navajo speakers to create a code that was never broken by the enemy.

If you want to push it further

  • Combine two ciphers into one message
  • Time how fast you can decode a message from a sibling or parent

Print it and go

The worksheet has the checklist, the prompts, and a space to draw in. One page, ready for a bag or a glovebox.

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