Between Silk and Cyanide: A Codemaker's War 1941-1945 by Leo Marks

In 1942, Leo Marks left his father's famous bookshop at 84 Charing Cross Road, and went off to fight the war. He was twenty-two and soon to be recognized as a cryptographer of genius He became head of communications at the Special Operations Executive (SOE), where he revolutionized the codemaking techniques of the Allies and trained some of the most famous agents dropped into occupied Europe.

The title is derived from an incident related in the book Marks was asked why agents in occupied Europe should have their cryptographic material printed on silk (which was in very short supply). He summed his reply up by saying that it was "between silk and cyanide", meaning that it was a choice between the agent's surviving by making reliable coded radio transmissions with the help of the printed silk, and having to take a suicide pill. Unlike paper, which would be given away by rustling, silk would not be detected by a casual search if it was concealed in the lining of clothing. Many of the incidents described in the book are humorous, a major theme is Marks' inability to convince his superiors that apparent mistakes made in radio transmissions from agents infiltrated into Nazi-occupied Holland were prearranged duress codes. S.O.E. management, unwilling to face the possibility that their Dutch network was compromised, insisted that the errors were attributable to poor operation by the recently trained Morse code operators and continued to parachute in new agents to sites prearranged with the compromised network This lead to their immediate capture and later execution by the Nazis. Marks' interest in cryptography dated from reading Poe's The Gold-Bug as a child. As a boy, Leo had begun his code-breaking with that of the used book store his father was a partner of, in noting the prices in his second-hand books.

Printing History

Written by Leo Marks (1920-2001)

HarperCollins

1998

ISBN 0-00-255944-7