The American Cryptogram Association
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.

2021 ACA Convention – August 20-22, 2021 – Hosted ONLINE by DARING FLAIR

This year’s convention will continue to be an online event, allowing for all members to attend from wherever they may live, while ensuring the safety and health of all. This convention will include our typical events – a social time on Friday, speeches on cryptographical topics on Saturday, and the annual general membership meeting on Sunday. In addition, the Convention Committee is proud to offer an additional Panel Discussion and special codebreaking event on Sunday evening! Click here for details.

Online registration is required and will begin July 1st, 2021.

Presenters Wanted for 2021 Convention – Share your knowledge of ciphers – either onsite or from the comfort of your own home! Contact vicepresident (at) cryptogram (dot) org with questions or if you are interested.

PayPal If you wish to use PayPal for paying your ACA dues or ACA For Sale items, please refer to the instructions on the membership page.

Free Web App. The ACA’s “Solve a Cipher!” program is now available as a free web app under the Resources tab. To access it, click HERE.

Tutorials for Sample Issue We now have tutorial solutions for all the ciphers in the free Sample Issue of The Cryptogram. Get your solving effort started with a nudge or follow along to see the complete solution of the cipher. It’s like looking over the shoulder of a friend solving a cipher.

THE RAT has upgraded his Conmaker program by adding the following cipher types in the “More Types” menu: CONDI, Nicodemus, Nihilist Substitution, Numbered Key, Phillips, Route, Sequence. The format of the program is slightly smaller and some minor error corrections and cosmetic changes were made. 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.