Appendix 12
Confirmed Cases of Allied Cipher Compromise in 1942
(This is from GCCS Enemy Intelligence Report #52, 18 June 1943)
Naval Cipher #3
Allied Message Contents German Ref. System Time Lag 1121/8/7/42 Movement of American Merships in North Atlantic. 29/7/42 # 3 "M" 20 days 0957A/20/9/42 Sinking of Norwegian freighter Olav Fortenes in 45°50'N - 42°00'W. 24/9/42 # 3 "M" 4 days 1802Z/21/9/42 Survivors of sinking of Olav Fortenes. 24/9/42 # 3 "S" 2 days 1753Z/5/10/42 Departure of Dutch submarine K-15 from Freetown. 13/10/42 # 3 "M" 7 days 1135/7/10/42 From Freetown radio, departure of unit, probably B.B. 20/10/42 # 3 "M" 12 days 1758/11/12/42 M.A.S. attack against Bone. (Italian and German foreknowledge of). 18/12/42 # 3 "S" 7 days
British Naval Cipher #4
Allied Message Contents German Ref. System Time Lag 1941A/12/8/42 Sinking of HMS Cairo. Captured Italian Doc #4 "C" Unknown 0949/15/8/42 Formation of convoy AP 1. 29/8/42 #4 "C" 14 days 1242/16/8/42 Unit from Kilindini via Simondstown to England. 30/8/42 #4 "C" 13 days 0506/22/9/42 English vessel Haresfield overdue in Indian Ocean. ? #4 (A3) 14 days 0958/25/10/42 NCSG Capetown to Admiralty quoted by Japanese on 1/12. ? #4 (A3) 37 days 0641/7/11/42 English transport left Archangel 7/11. 13/11/42 #4 (A1) 6 days 2120/23/11/42 English submarine left Malta 25/11 for antisubmarine duties CJ 7195. 3/12/42
(also by Italians)#4 (C) 10 days
British Naval Code
Allied Message Contents German Ref. System Time Lag 1359A/23/10/42 British trawlers on fixed patrol. Orkney - Shetlands - Faroes - Iceland area. 28/10/42 (K 1) 4 days
Auxiliary Table Area 1 (I 1)
Allied Message Contents German Ref. System Time Lag 2330/11/11/42 British Merships (2) in area north of Petsamo. 15/11/42 4 days ?/19/11/42 British Bramham arriving Philippeville. 3/12/42 14 days 1302A/26/11/42 British antisubmarine trawler received information on mines in area Melilla. 2/12/42 6 days
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