Many thanks to Mike Cowan for a link to an internal sub-tree of The National Archives (UK) with a plethora of links to valuable cryptographic material related to the Government Code and Cypher School (GCCS) and Government Communications Headquarters (GCHQ) between the years 1914-1979.
Quoting from the web site, the site contains “general records of the Government Code and Cypher School (GCCS) and Government Communications Headquarters (GCHQ) relating to responsibilities for intercepting enemy communications, particularly during the Second World War, and for ensuring security of the government’s electronic communications“.
The records span the years 1914-1979 and included the following general categories:
- Senior management papers
- Soviet communications
- Japanese military communications
- Histories and personal papers
- German military communications
- Bulgarian, Croatian, French, Iranian, Italian Portuguese and Spanish communications
- Diplomatic, commercial and meteorological communications
- Liaison with allied organisations
- Communications security
- Field signals intelligence
- Technical matters
- Intercepted plain language communications
- Wireless Telegraph Section
- GC&CS Administration
- Research Section
For those with access to the National Archives in London, there is material here to keep one busy for years.