Wartime notebooks and prototype materials from Alan Turing's secret "Delilah" project have been secured for the United Kingdom following a temporary export ban.
The preservation of these documents prevents the loss of significant historical assets to foreign buyers. The materials provide a rare glimpse into the clandestine work of the British mathematician and code-breaker during the Second World War.
Created between 1939 and 1945, the Delilah project focused on secure communications. The documents were officially secured for the nation in February 2025 [1]. These papers are currently valued at nearly £400,000 [2].
Reports on the nature of the materials vary. Some accounts said the project was a prototype communications device intended to transform military communication [1]. Other reports said the notebooks contain unpublished code-breaking work rather than a specific device [3].
The papers were reported from the West Midlands region of the UK [4]. The export bar ensured that the documents remained within the country for public and academic study. This move follows a period of limited visibility for the project, which remained largely secret for decades after the war ended.
Turing's contributions to the war effort are well-documented, but the Delilah materials offer a more specific look at his technical approach to voice encryption and signal security. The notebooks represent a physical link to the intellectual processes Turing used to protect Allied communications from enemy interception.
“The documents were officially secured for the nation in February 2025.”
The retention of the Delilah notebooks in the UK underscores the high cultural and intellectual value placed on Turing's wartime legacy. By preventing the export of these materials, the UK ensures that scholars can analyze the evolution of secure communications and cryptography without the barriers of private ownership abroad.
