Decoding Auschwitz
Christian Jennings

Decoding Auschwitz is a big, important and new story about the Holocaust, about codebreaking and about WW2. Contrary to the historiography established over the last eighty years, the Allies did know about operations at the Auschwitz-Birkenau camp complex for most of the war, via codebreaking and other intelligence. They then suppressed their evidence of the railway deportation operation of Europe’s Jews, and many of their subsequent killings, to help protect the source of the information: the vital, war-winning secret of Ultra, and Enigma.

However, the Allies and neutral countries did do something to try and fight back against and impede the persecution of Europe’s Jews, in a complex four-year series of operations involving Russian, British and American intelligence, the Red Army, the US Air Force, resistance groups across Europe, the International Red Cross and the Vatican.

How did British, American and Soviet codebreakers really uncover the coded secrets of the Third Reich’s deportation programme of more than a million of Europe’s Jews to Auschwitz-Birkenau, and their subsequent extermination? What was known, when, how, and across fifteen countries, what was really done about it?  

Decoding Auschwitz tells the story from the points of view of four narrators: a British cryptanalyst at Bletchley Park breaking into SS  coded signals from Auschwitz, an Austrian SS officer working with Adolf Eichmann on the railway deportation programme of Europe’s Jews, and an American female cryptanalyst breaking into crucial Japanese, German and Soviet ciphers. For the first time the story is told from a Soviet perspective as well, through the eyes of a senior Russian NKVD officer running codebreaking operations in Moscow.

The book includes decrypted top-secret SS signals sent from the commandant of Auschwitz, to Enigma-encoded messages, sent by SS concentration camp commanders to the Gestapo, to original SS railway deportation orders and Soviet signals from Moscow to communist partisan and revolutionary groups across wartime Europe, and decrypted diplomatic signals from twenty different countries.

It describes the Soviet penetration of Bletchley Park, as Moscow hunted for top-secret coded information from the American atomic weapons programme, the Allied operations against German SS nerve gas laboratories at Auschwitz, the Red Army and Polish partisans’ battles against the railway networks leading to extermination camps in Poland, and untold, new stories of the International Red Cross and the Vatican going head-to-head with the SS in Italy, Romania, Hungary and Slovakia.

The book draws on decrypted signals and new and existing archive material held in nineteen capitals and countries, predominantly London, Jerusalem, Moscow, Berlin, Washington, Rome, Poland, Geneva, The Hague, The Vatican and Tokyo, but also Ankara, Oslo, Paris, Stockholm, Helsinki, Brussels, Bucharest, Belgrade and Vienna.

The British historian Dr Helen Fry has said that the author’s previous book, The Holocaust Codes, “is the most important Holocaust research in more than a generation.” This book takes the story a huge step further.