March 6th, 1942 (FRIDAY)
GERMANY: When AT&T started transatlantic radiotelephone in the 1920s, it scrambled the calls to protect against interception.
The Deutsche Reichspost, which handled telecommunications, realised that the calls might provide useful intelligence. Kurt Vetterlein, one of the young engineers of the Forschungsanstalt, cryptanalysed the privacy system. Today, the German postal minister, Wilhelm Ohnesorge (party number 42), writes to his Führer to report this success. He appends an intercept of 7 September 1941 between two British officials.
The Reichspost set up an intercept post in a youth hostel on the Dutch coast near Noordwijk, later moving it to a brick-and-concrete bunker at the intersection of Nieuwe Waalreseweg and De Hazelaar streets in Valkenswaard.
The unit intercepted no fewer than 30 calls a day, and sometimes as many as 60. A half dozen interpreters listened to them and chose the most valuable.
Most talks were between medium- and high-level officials.
But Churchill liked the telephone and rang Roosevelt at all hours. They and a few other high officials were not given the warnings about telephone insecurity that other officials were, which the Germans took as an indication that an important person was coming on the line. The speakers were sometimes indiscreet.
But allusions and incomplete references made it hard for the Germans to gain much intelligence from the talks. The most pregnant sentences in a conversation between Churchill and Hopkins were "Can you give me any hopeful answer?" and "Yes."
Roosevelt-Churchill conversations told the Germans only that the cross-Channel invasion was coming closer and hardened the German decision to get troops into Italy after the collapse of Mussolini’s government. None provided any extraordinary insight into Allied plans. As a German Foreign Office official disappointedly noted on a sheaf of intercepts, "There is in general not much to be gotten from them."
Nevertheless, the Americans, aware of the weakness of the AT&T scrambler, developed a much superior system, codenamed SIGSALY. It provided the acoustic equivalent of the one-time pad
– the only theoretically and practically unbreakable cryptosystem. Requiring bays of electronic equipment and many phonographic disks of random sound that were destroyed after one use, SIGSALY terminals served the White House through an extension, Churchill’s underground offices also through an extension, and other Allied headquarters worldwide. High officials used it, and it seems never to have been intercepted, much less solved, though the older AT&T system seems to have c0ontinued in use.The president and the prime minister also communicated using written messages over the transatlantic cable. These were encrypted. (Ed Miller)(235 pp. 554-557, 449-500)(236 pp. 172-176)(237)(238, pp. 70-80)
U-535 laid down.
NORWAY: The German battleship
Tirpitz sets sail from her base in Trondheim to intercept the ships of convoys
QP-8 and PQ-12 sailing from Iceland to Archangel, U.S.S.R. Despite information
sent to the British aircraft carrier HMS Victorious, no contact is made between
the forces. The British Admiralty draws criticism because of its inaction.
ROMANIA: The government breaks diplomatic relations with Brazil.
SPAIN: Madrid severs diplomatic relations with Norway.
MEDITERRANEAN SEA: HMS Eagle ferries 18 Spitfires to Malta, while seven Blenheim bombers fly in from North Africa.
BLACK SEA: SMYSHLENY, Soviet Destroyer, Mined in the Kerch Straits.
BURMA: The newly arrived British
63d Brigade, under command of the Indian 17th Division, makes a futile effort to
clear the block on the Rangoon-Pegu road and relieve the Pegu garrison, which is
isolated. Lieutenant General Sir Harold Alexander, General Officer Commanding
Burma Army, orders Rangoon evacuated since the situation in lower Burma is
deteriorating rapidly; a denial program is to be put into effect at 0001 hours
tomorrow.
CHINA: U.S. Lieutenant General Joseph Stilwell, Commanding General American Army Forces, China, Burma, and India, confers for the first time with Generalissimo Chiang Kai-shek in Chungking.
NETHERLANDS EAST INDIES: On Java, the Japanese advance has sealed the Australian, British, Dutch and U. S. defenders into two pockets, one in the central highlands, the other near Surabaya, the Dutch naval base.
JAVA SEA: JAN VAN AMSTEL, Dutch Minesweeper, Sunk in Madura Strait by surface action
PIETER DE BITTER, Dutch Minesweeper, Scuttled at Soerabaja
ELAND DUBOIS, Dutch Minesweeper, Scuttled in Gili Genteng Roads, Java
(James Paterson)
CANADA:
HMC ML 066 commissioned.
U.S.A.: The motion picture "To Be or Not to Be" opens at the Rivoli Theater in New York City. Directed by Ernst Lubitsch, this comedy about Poland in World War II stars Jack Benny, Carole Lombard and Robert Stack. This was Lombard's last film.
Submarine USS Scamp laid down.
Submarine USS Amberjack launched.
ATLANTIC OCEAN: German submarine U-129 torpedoes and sinks an unarmed U.S. freighter SS Steel Age about 130 miles (209 kilometres) northeast of Paramaribo, Dutch Guiana, at 06.45N, 53.15W, and takes the sole survivor captive. 33 crewmembers are lost.
Motor tanker Sydhav sunk by U-505 at 04.47N, 14.57W.
U-587 erroneously reported the name of the ship as Hawse Gude, but it must have been Hans Egede, which was reported missing in Canadian waters on 4 March.
At 2306, steam trawler Rononia was hit amidships by one torpedo from U-701, broke in two and sank within a few seconds.