Holocaust Codes by Christian Jennings

‘Massive, groundbreaking new research that sheds more truth on the Holocaust.’ – Helen Fry

Never told in detail before, this is the account of how, for four years, British and Allied codebreakers decrypted secret SS and Gestapo messages detailing the mass killings of the Holocaust, and how the Germans in turn deployed cryptanalysis to try to conceal their persecution of Europe’s Jews. The compelling and fast-paced narrative is told from the perspectives of two central and opposing characters, who never meet.

At Bletchley Park, there is the legendary but unsung British codebreaker Nigel de Grey, shy, determined, nicknamed ‘the Dormouse’ by his colleagues. In Nazi-occupied Poland, SS Major Hermann Hoefle, a former taxi driver from Salzburg, and one of the Third Reich’s ruthless bureaucrats of mass death, oversees the operations of five concentration camps, including Treblinka.

De Grey fought hard to make sure the vital intelligence from decrypted signals reached Allied leaders and was acted on. Hoefle, meanwhile, used complex coded messages to try to conceal the mass killings. De Grey worked with his American counterparts, as well as codebreakers and intelligence agents from the Soviet Union, France, the Vatican, Switzerland and Poland. Yet he had dangerous enemies closer to home: a cabal of senior British government and intelligence officials disbelieved or ignored repeated intelligence reports about the ongoing Holocaust.

Flawlessly researched, this is the story of a battle between good and evil, between life and mass death, a cat-and-mouse war of electronic wits. More than eighty years on, as Russian leaders face war crimes charges in international courts, the words ‘Never again’ seem more pertinent than ever.

The first dedicated study of the cat-and-mouse struggle between a British cryptographer at Bletchley Park, and an Austrian SS officer responsible for the mass killings of thousands of Russian and Polish Jews. The account of how Nigel de Grey cracked the Enigma-coded signals of SS Major Hermann Hoefle is one of the greatest untold stories of the Second World War.

About the Author: Christian Jennings is a British author and foreign correspondent, and the author of ten non-fiction books of modern history and current affairs. These include the acclaimed The Third Reich is Listening: Inside German Codebreaking 1939-1945, the first comprehensive account in English of German wartime cryptanalysis. His latest book is Syndrome K: How Italy Resisted the Final Solution. He has lectured for Bletchley Park on German codebreaking, and from 1994-2012 he spent fifteen years reporting on international current affairs and complex war crimes investigations, including genocide and its aftermath, across twenty-three countries in the Western Balkans and Africa. He has written for publications ranging from The Economist and Reuters to Wired, The Guardian, and The Scotsman, and as a foreign correspondent was based in Rwanda, Bosnia, Kosovo, Burundi, Kenya and then Switzerland.

05 Jun 2025
 

The Holocaust Codes: The Untold Story of Decrypting the Final Solution by Christian Jennings ISBN 9781789467277