Craig P. Bauer is a professor of mathematics at York College of Pennsylvania. He’s the editor-in-chief of Cryptologia and was the 2011–2012 Scholar-in-Residence at the National Security Agency’s Center for Cryptologic History. He loves to carry out research, write, and lecture. His previous books are Secret History: The Story of Cryptology and Unsolved! The History and Mystery of the World’s Greatest Ciphers from Ancient Egypt to Online Secret Societies. With the present book he stays true to his style, blending mathematics and history. Craig earned his Ph.D. in mathematics from North Carolina State University and did his undergraduate work at Franklin & Marshall College.