You know that X marks the spot… but what about all those other enciphered letters?

Many geocachers stumble onto an enciphered cache as they look for more challenging puzzles to solve. But what do you do when faced with a series of meaningless symbols or letters? Mastery of land navigation, the magnetic compass, topographic maps, and handheld GPS doesn’t prepare you for cryptanalysis!

The American Cryptogram Association is here to help. Cryptogram solving and geocaching are complementary skills, and many members of the ACA “krewe” are also avid geocachers. Geocachers and cipher-solvers both enjoy the pursuit of a clever solution to a complex puzzle and use all possible data at their disposal to get to the result. Both hobbies emphasize exploration, discovery, and collaboration, and reward those with an analytical bent. Here are some ways we can help you add cryptanalysis to your tool set:

• The ACA maintains a list of manual ciphers that may help you assess the cipher and see what ciphers could possibly fit. If you have some hints on what cipher type might be used, this list of ciphers describes our rules for encryption. Take a look at these options and see if the cipher in your hands follows the rules you see in our cipher descriptions.
• Once you have a cipher type, some ACA members have published tools to analyze ciphers and help you solve them. ACA members BION, THE RAT, and MiB all have cipher solving tools online. None of these sites will solve the cipher for you – but they will present you with tools that can automate the process and let you try lots of ideas more quickly. BION and THE RAT offer multiple “ID tests” that will compare a cipher to a database of cipher types and use statistical analysis to suggest the most likely encryption method. Both BION and MiB offer “crib dragging” for several cipher types. Crib dragging allows one to place the crib (suspected word or phrase), showing all its proper possible places. Many times, a cipher’s structure ensures that a crib can only be placed in a few places – if at all! If there’ a term you are sure appears in the message, crib dragging can be a powerful method to break an enciphered message. Several other downloads and resources are available free of charge from the ACA’s resources page.
• The ACA offers you a tool that can immediately strengthen your cipher-solving muscle – our “Solve a Cipher” app. This app is loaded with a library of simple substitution ciphers you can solve right away and get instant feedback on your guesses. Using your knowledge of the English language and your intuition, you’ll be surprised how quickly you can tackle and master the Aristocrat of puzzles.

If you find yourself wanting more, check out our sample issue of the Cryptogram, our journal and magazine. It will give you a taste of what ACA members receive six times a year with a range of ciphers to attack. This sample issue also explains some of our special terminology. If you get stuck, a tutorial is available that will walk you through each cipher. You can also talk to dedicated hobby cryptanalysts on our Facebook group and on our Google group.

Finally, we’d love to have you as a member if cryptography strikes your interest! Members get more than 600 carefully-curated ciphers to solve each year, as well as useful cryptographic articles and an invitation to a yearly cryptographic convention. Learn more at www.cryptogram.org!