0329

File Title 'C', Chief of the Secret Intelligence Service (SIS): Reports and Information; Blue Jackets (BJs)
Reference FO 1093/329
Date 24 December 1943 - 8 December 1944
Government Department Foreign Office
File Accession Date 23 May 2013
Notes A number of documents within this file have been retained under Section 3(4) of the Public Records Act, 1958.

Description

A file of correspondence and memoranda concerning the secrecy and circulation of signals intelligence during the Second World War. Subjects discussed in this file include the changing of Japanese cyphers; German intelligence sources in the Chilean army; the security of allied cyphers; the exchange of ‘Ultra’ decryptions with the Americans; security and censorship arrangements for Operation Overlord, including information leaks to American newspapers and a Brazilian diplomat; a debate over the circulation of classified signals intelligence within the British intelligence services; and an intercepted message from the German embassy in Lisbon to Berlin reporting a recent speech by Winston Churchill, and drawing conclusions about Anglo-Soviet relations.

Document Title Date
i Front Cover Download PDF (534 KB)
1st 'C', Chief of the Secret Intelligence Service (SIS): Reports and Information; Blue Jackets (BJs) Download PDF (28.26 MB)
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