How Cryptograms Function

Have you ever sent a covert message, maybe to outwit someone or to keep a surprise under wraps? We all send secret notes from time to time, and cryptograms are a fun way to do it. These puzzles use number or letter substitutions to obscure the meaning of a word or phrase. If only the sender and the intended recipient know the code, the message remains an enigma.

Throughout time, cryptograms have served as a means of safeguarding some of the most confidential information. A notable example is the Zimmerman Telegram, sent during World War I by German Foreign Minister Arthur Zimmerman to the German ambassador in Mexico, Heinrich von Eckhart [source: National Archives]. Zimmerman used a numeric cipher to propose that Mexico gain U.S. territory in exchange for supporting Germany against the U.S. The British cracked the code quickly, and just weeks later, the U.S. entered the war on the side of the Allies.

There are various methods to encrypt a message using a cryptogram. One straightforward example is the substitution cipher, where each letter in the alphabet is paired with a different letter. For instance, "A" becomes "Z," "B" turns into "Y," and so on [source: Puzzle Baron's Cryptograms]. Another option is the Caesar cipher, where each letter is shifted by a specific number of places. For example, a Caesar cipher with a shift of one would turn 'DOG' into 'EPH' [source: Trinity College].

Historically, cryptograms have been used by politicians, spies, lovers, and even clever teenagers seeking to shield their secret conversations from their parents' inquisitive eyes. Today, they are increasingly popular as brainteasers, with numerous websites and mobile apps dedicated to solving cryptograms and cryptoquotes, which are cryptograms based on well-known quotes [source: Donahue]. In the following section, we'll explore some of the essential strategies for solving cryptograms.

How to Solve Cryptograms

Cracking a cryptogram requires patience, focus, and a bit of strategy. Fortunately, you don't have to tackle it alone. There are many different methods for solving cryptograms, just as varied as the puzzles themselves. Begin by searching for repeating patterns in the text. Are any particular letters more frequent than others? This is called frequency analysis, a great starting point for solving cryptograms [source: Puzzle Baron's Cryptograms].

As a cryptography detective, ETAOIN is your most valuable ally. It’s a mnemonic that represents the most frequent letters in the English language in order of occurrence. This is crucial to keep in mind. If a letter in a cryptogram appears significantly more often than the others, it’s likely that it corresponds to one of the letters in ETAOIN, with a higher chance of being 'E' or 'T.'

When tackling a cryptogram, start by focusing on the shorter words. In English, there are only two one-letter words: "I" and "A." Look for single letters that could correspond to one of these. Occasionally, you may encounter the archaic letter "O" (e.g., "O, say can you see…"), but it’s uncommon. Apostrophes are also useful markers in cryptograms, as they typically occur in contractions or possessives, making them easier to identify [source: Puzzle Baron's Cryptograms].

Once you move beyond short words, solving anything longer than three letters in a cryptogram can be trickier. It helps to focus on digraphs, which are pairs of letters that form a single sound, such as "CH," "SH," and "TH." If you spot the letter "H" in a cryptogram, look for other places where it appears, especially at the end of words, as it’s often part of a digraph. Double consonants and vowels are also key to uncovering the message.

When solving a cryptogram, it's crucial to consider the theme if one is provided. This often gives a helpful clue about the hidden phrase or quote. These techniques can help decode many common cryptograms—and perhaps even some more challenging ones. However, even expert codebreakers spend a lot of time simply staring at the puzzle, waiting for the hidden message to unfold.