Secret Codes of Early America

This presentation is about the Secret Codes used in the first 100 years of American history, particularly the Revolutionary War through the Civil War. It is not about how codes affected history, but how the codes actually worked, how they were created and how they were broken; how you can make them, and how you can break them.

It covers substitution ciphers, crypto analysis, Dumas and Stager ciphers, grille codes, disks and wheels, book codes, the Playfair cipher, null ciphers, transposition ciphers, and invisible ink.

Richard Hubert, a long-time resident of Newtown, CT and a current resident of The Villages, is a retired software engineer with a background in electrical engineering and business. He is a former US Navy officer and worked with crypto systems during the Cold War.