Cryptogram: Custom Message

Your message, enciphered

Every letter is swapped for a different one, consistently throughout, and the solver works out the mapping from the pattern. Type a quote, a motto, a birthday message or a clue for a treasure hunt, up to about 350 characters.

Spaces and punctuation stay where they are, which is what makes the puzzle solvable — word lengths and apostrophes are most of the evidence.

Difficulty is the number of letters given away

• Easy reveals six to ten letters, weighted towards the common ones. Enough to see several whole words at a glance and work outward from there.
• Medium reveals three to five. A foothold, and then real work.
• Hard reveals nothing, or almost nothing. You start from the structure alone.

The starter letters are chosen from the frequent ones on purpose. Being given a Q is nearly useless; being given an E unlocks the shape of the whole text.

How to solve one

Start with the one-letter words. In English they are almost always a or I, and getting one of them right usually confirms itself immediately.

Then look for the apostrophes. A letter after an apostrophe at the end of a word is s, t, re, ve, ll or d, and that is a very short list.

Then count. E is the most common letter in English by a distance, and the most frequent symbol in a text of any length is usually it. T, A, O, I and N follow.

Finally, look at three-letter words. The is the most common word in the language and its pattern is distinctive once you have a candidate for E.

Choosing text that works

Longer is easier, which is the opposite of what people expect. A hundred-character quote gives the solver enough repetition to count letters; a fifteen-character motto gives almost nothing and turns the puzzle into guesswork.

Ordinary words help. A text full of names and unusual vocabulary breaks the frequency logic, because the solver's instinct for what a word could be stops working.

Avoid numbers and unusual symbols — they do not encipher and they interrupt the pattern.

Where it earns its place

A cryptogram is a way to make somebody read a sentence slowly and carefully, which is otherwise difficult to arrange.

That makes it good for a message you want remembered: a class motto, a birthday note, the location of a hidden present. It also makes a decent introduction to frequency analysis, which is a real technique and the reason simple substitution ciphers stopped being used for anything serious several centuries ago.

The options

Your text, the difficulty, how many puzzles to print, and the answer key. A4 or US Letter.

Print at 100% on A4 or US Letter.