Misread Signals (How History Overlooked Women Codebreakers)

“It is inspirational.” – Helen Fry, author of Women in Intelligence

“An important and exciting contribution to history.” – Clare Mulley, author of Agent Zo

Bletchley Park is often remembered as a world of brilliant male intellectuals—Alan Turing, William Tutte, and John Tiltman—supported by women in clerical roles. These men worked on the formidable Enigma and Lorenz cipher systems, helping to turn the tide of the war in the Allies’ favor.

But that’s not the full story. Women were not just secretaries or assistants; many were accomplished codebreakers in their own right. And their work wasn’t limited to Bletchley, to Britain, or even to World War II.

Misread Signals reveals the remarkable women whose contributions have long been overlooked: Margaret Rock, who solved Enigma and other machine problems; Agnes Driscoll, the U.S. Navy’s pioneering codebreaker; and Asta Friedrichs, who after the war became a key source on German Foreign Office cryptography. These women—and many others like them—helped shape the course of intelligence history, only to be written out of it.

Who were they? What did they accomplish? And how did they “vanish”? In Misread Signals, expert codebreaking historian Dermot Turing restores these women to their rightful place in history, shining a light on their extraordinary and long-forgotten achievements.