William and Elizebeth Friedman were both researchers in cryptography at The Riverbank Laboratories. This 1957 book is the result of an insightful report that won the Friedmans the Folger Shakespeare Library literary prize. Within it the Friedmans address theories which through the identification of hidden codes call the authorship of Shakespeare s plays into question. As ciphers were abundantly used in the sixteenth century such coding is far from impossible. Accordingly this work gives a fair and scientific hearing to those anti-Stratfordians whose theories were often dismissed completely. The Friedmans document the history and foundations of such theories before thoroughly examining and critiquing a great number of them. Indeed it has even been suggested that this text itself contains ciphers making it of even greater interest to scholars of literary codes and cryptography as well as those wishing to discover more about the various debates surrounding the authorship of Shakespeare s plays.