Puzzle 4: frequency analysis

 

The sender and recipient can communicate as long as they know the cipher alphabet. The weakness in this system is that the English language is structured and each letter appears with a certain frequency. This means that the cipher letter will appear with the same frequency.

 

Here are the letters of the alphabet with their associated percentage frequencies in the English language:

Remember that this is an average frequency and short messages may not contain these exact frequencies.

 

The message below has been encrypted using a random cipher alphabet. Use the frequencies above as a guide to recovering the plaintext letters and once you have a few then guess some common English words that fit around these letters.

Use the table below to help you record the frequencies of the cipher text letters. Use these frequencies to help guess at the plain text letter associated with each cipher text letter:

Answers