History books that focus on World War II are often peppered with accounts of military strategy and action, or reports of brave soldiers fighting and dying far from their homes to preserve freedom. Seldom featured are the everyday men and women who contributed to the war effort behind the scenes. Liza Mundy's latest work, Code Girls, takes advantage of recently declassified government documents to highlight the little-known work of the hundreds of women involved in cracking Japanese and German encryption to help bring WWII to a successful conclusion.

The code-breakers' stories are not only fascinating, they're enlightening; unbeknownst to most, their contributions had far-reaching effects long after the war and cannot be overstated. The author writes of these women: "They laid the groundwork for the now burgeoning field of cybersecurity, which entails protecting one'...