Code Breaking Puzzle Hints

One kind of code breaking puzzle, sometimes called a cross reference, is based on what are known as substitution ciphers. Each letter in the code message is simply substituted for a different character or letter consistently. For much of history this was the main kind of encryption used from the Caesers to the Elizabethans. They are very easy to break though with a bit of patience and practice. Once empires depended on them. Now they are just for fun.

Here are a few tips to get you started.

• As soon as you have worked out a letter fill it in everywhere. Double check for ones you've missed.
• Count how often each number occurs. The common ones will stand for common letters. This is known as frequency analysis. Make guesses at letters based on their frequency.
• The most common letters in large bodies of English are E,S,A,R ...
• Take care though, as in small amounts of writing or unusual passages the frequencies can be different.
• Look for the positions that the letters commonly occur in - S for example often comes at the end of a word.
• When you have some letters filled in, look for positions where vowels are likely to appear.
• Keep a list of letters and cross out those that have been used already. Crossword style code cracking puzzles often use all the letters of the alphabet.
• Try and work out E first - it will be very common, possibly the most common, and as it's a vowel, so its position in words may help.
• Look for short words - they must have a vowel in (or unusually a y).
• Q is a good letter to look for early. It is always followed by U in English, so look for distinct pairs. The second of the pair could appear elsewhere in vowel positions.
• When you have some letters in, guess at words, then check to see if the letters fit in all the other positions.

Try a code breaking puzzle.