Cambridge: At the University Press 1957. Later printing. xvi, , 302,  pages. 8vo (5 3/4 x 8 3/4 inches) Publisher's grey cloth with red and black printed dust jacket. The second printing, issued in the same year as the first, 1957. Dust jacket noting "Second impression" and with five dollar retail price. Dust jacket with lower corner clipped, some scuffing to the rear panel and with minor wear at the extremities. Binding with touch of shelf wear on the bottom edge. First two gatherings slightly proud of the rest of the textblock with some of the internal stitching showing in the gutter as if opened for copying just a bit too far. Still sound. NOTE: the rear dj flap still has affixed the original "fold-under" tear-out bookmark on Bacon's bilateral cipher.
Ink SIGNED on the half title page by AUTHOR Elizebeth S. Friedman: "1974 Elizebeth S. Friedman For William F. Friedman" Very Good / Near Fine. Cloth. 
The Friedman's were famous cryptologists during World War I and were instrumental in breaking codes during that war. Many secret works by William Friedman's were published through the Riverbank Laboratories where he and Elizebeth met. After retirement, they continued with a lifelong hobby, examining Shakespearean Ciphers, and objectively evaluating their efficacy. This book is the result. Scarce signed by either author. William F. Friedman died in 1969. Elizebeth S. Friedman died in 1980.