The American Cryptogram Association (ACA) is a non-profit organization dedicated to promoting the hobby and art of cryptanalysis -- that is, learning to break ciphers.

Join Us!

Now is an ideal time to join the ACA. While supplies last, new members will receive a CD-ROM containing the contents of The Cryptogram from 1932 to 2009. For information on membership benefits and details on how to join see Membership.



Kent State University Cryptology Collection

Currently have an exhibition on display our cryptology collection. Exhibition closes August 9, 2016. If any ACA Members are interested in having a guided tour of the exhibit or otherwise visiting, Please contact Cara directly.
Cara Gilgenbach
Special Collections and Archives
Associate Professor Kent State U. Libraries
1125 Risman Dr. - Kent, OH 44242


If you wish to use PayPal as an option for paying your ACA dues or ACA For Sale items, please refer to the instructions on the membership page and use the fee calculator to get the correct amount.

Free Web App.

The ACA's "Solve a Cipher!" program is now available as a free web app for users of Google's Chrome web browser. To get it, click HERE, or go to the Chrome Web Store and search on "ciphers".

New Expanded Free Sample Issue

The free sample issue of The Cryptogram available for download has been expanded with more explanations and many more ciphers to solve. Read about it and download it on the Sample Issue page under About the ACA .

2nd Edition PHOENIX Memorial CDROM

A member reported that the links on the index page of the 2nd Edition PHOENIX Memorial CDROM did not work with Acrobat Reader v9. It turned out to be caused by the default value of a preference option. Here is how it was corrected:


Documents->View Documents in PDF/A mode: NEVER

From the Edit menu, select "Preferences", then choose to look under Category "Documents".

The option "View Documents in PDF/A mode" should be changed to "Never".

FBI Code Breaking Challenge.

The FBI has a website with a code breaking challenge. Check it out.

THE RAT has made available for ACA members a program called Conmaker. It is designed for Windows users to easily create and submit cons to the ACA column editors. If interested, go to the Members Area / Downloads and get your copy.



2016 ACA Annual Convention Dallas/Fort Worth, Irving, TX

ACA’s 2016 convention will take place in Irving, TX, September 9-11, 2016. Your hostess, HONEYBEE (, is making arrangements and plans to ensure this is a most pleasurable and enlightening event. Get your cowboy hat and boots ready for a boot-scooting good time!

We hope you will join fellow members of the Krewe in this opportunity to meet and interact with others who share your enjoyment of what is admittedly a pretty specialized area of interest. Come and share your knowledge of cryptology—from historical aspects to solving methods—with fellow members. During your visit, take advantage of the opportunity to do some sightseeing in the Dallas/Fort Worth area.

The convention hotel will be the Wingate by Wyndham Hotel located at 850 W Walnut Hill Lane, Irving TX 75038; telephone: 972-751-1031. We have negotiated a rate of $89.00 per night (plus taxes). These rates apply during the period September 9-11, 2016.

For those wanting to arrive up to three days before or stay three days after the convention, there is a negotiated rate of $99.00 per night (plus taxes) for September 6-8 and 12-14, 2016.

The hotel offers its guests all of the usual amenities, including free shuttle service to and from Dallas-Fort Worth International Airport (DFW) during the following hours (Sunday-Thursday: 7am to 10:30pm, 10pm is the last call of any pick ups or drop offs & Friday-Saturday 7am to 8pm, 7:30 is the last call of any pick ups or drop off); complimentary hot breakfast, air-conditioned, free parking, smoke-free, kitchen in all rooms, business center, newly remodeled fitness center, and more.

Hotel reservations may be made now, but must be made by August 15, 2016, to be eligible for the group rate. Please call the hotel directly at 972-751-1031 and identify yourself as a member of the “American Cryptogram Association.” (Do not make your reservation through a travel agent or on-line: This will ensure that you get the group rate. It also gives ACA credit with the Wingate for your attendance, which helps keep convention costs down.).

A wide range of activities is being considered for the Krewe, including sight-seeing, museums (arts, science, history, natural history in Dallas and Fort Worth), botanical gardens, sporting facility tours, water parks, amusement parks, shopping and more. This list is being generated at the present time and will be an ongoing project. Some of this is mentioned now to help those members and spouses planning to arrive early or to stay late. More information will be posted as the information comes together.