Caesar Wheel

Use the Caesar wheel to decipher the following message: MLORPC (Clue: it is an animal that begins with ‘b’).

How many different ways are there to send a Caesar shift?

Try shifting the wheel 13 places (so `a’ becomes `N’). This shift is special, can you see why. (Clue, try coding and decoding your name).

The Caesar wheel has one alphabet on the outside wheel, and another alphabet on the inside wheel. The inside wheel can then rotate so we can replace one letter for another.

For example, a shift of 3 will turn the word penny’ into the cipher SHQQB’.

In this example, each letter is replaced with a letter 3 letters further down the alphabet. To decrypt a message, you just need to use the wheel in reverse.

Notice that the alphabet then wraps back to the beginning, so ‘y’ becomes B. This kind of wraparound adding is like how a clock wraps around and is called modular, or clock, arithmetic

There are 26 ways to shift the alphabet, including going all the way back to the beginning. To break the code, you just need check all 26 possible shifts, which doesn’t take very long, so this cipher is too easy to break.