Code Cracker

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Need help? Here is a Code Cracking slide presentation.

Drag the letters on the yellow tiles above to replace their coded equivalents in the message. Correct replacements will stay in place while errors will return to the alphabet. Click the button on the right to get a hint which may help you crack the code. There are many hints available and viewing them won't affect your score. Your score will be the percentage of letters you decoded correctly minus the number of mistakes you made. There are three levels and you can earn a Transum Trophy for completing each level. That is correct. You have successfully cracked the code and decyphered this . Click on the button below to claim a trophy.

Progress Mistakes Score

Suggested Starter Freemason's Cipher Can you work out how to use the Freemason's or Pigpen Cipher? Can you find any words in the Freemason's Cipher which are symmetric? What is the longest one you can find?

Clue Challenge Letter Clue Calculations Write down a calculation involving single digit numbers. Write the numbers in the calculation in words. Choose just one letter from each of your words and give this clue to a friend. Can your friend work out what your calculation was?

Try Texting Texting A code breaking exercise based on the use of a mobile phone. Unfortunately Mary's teacher did not know how to use the predictive text facility so the wrong words were sent. Can you figure out the correct answers?

Another activity on the Transum website requiring you to figure out the letters used in hidden words is called Shark's Dinner? In what order should you choose letters? The obvious answer would be to find a list of the most common letters used in the English language and use this as your letter selection order.

You may be surprised to hear that this is not necessarily the best strategy. Words of different lengths will have different letter frequencies. Also when you have established whether are particular letter is or isn't in a word your next choice should be affected by that knowledge.

Tom Whipple is the science editor for The Times in London and in an eposode of the Freakonomics podcast he talked about his book How to Win Games and Beat People in which he discusses strategies that might be used when playing games similar to Shark's Dinner. Here is an extract from the podcast:

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