Rockex

A Rockex at the Bletchley Park Exhibition (2006)

The Rockex (also: ROCKEX ), British BID device names BID / 08/05 , BID / 08/06 , BID / 08/07 and BID / 08/08, was an American-British key machine for the encryption of telex , which cryptographically secure one-time key procedure ( English one-time pad , short: OTP ) used.

history

Camp X was near the Canadian-American border in Ontario (1943)

The machine was developed during the Second World War from 1940 at the request of the British secret service in the United States by the Canadian electrical engineer Benjamin deForest Bayly , put into service from 1943 and from 1944 by the HMGCC ( His Majesty's Government Communications Center ) in Hanslope Park near Milton Keynes manufactured. It was an improved further development of Telekrypton , a forerunner developed around 1933 by the American Western Union Telegraph Company . In contrast to this, Bayly has eliminated some cryptographic weaknesses at Rockex , for example the transmission of carriage returns , line feed and letter-digit switching . The ciphertext of Rockex consisted exclusively of the 26 letters of the Latin alphabet . This allows the encrypted telex to be easily transmitted over the commercial communications networks.

The components of the Rockex were supplied from Chicago by Teletype Corporation , an American manufacturer of teleprinters at the time .

The Rockex was used from 1943 in transatlantic communications between the war- allied USA and Canada on the one hand and the United Kingdom on the other. The first Rockex connection across the Atlantic was established by the British Security Coordination (BSC) between Camp X near Whitby on Lake Ontario and Station X in Bletchley , UK . Shortly afterwards, further Rockex connections were installed between New York or Washington and London , through which practically the entire secret exchange of messages between the British Secret Intelligence Service (SIS) or the Government Code and Cypher School (GC&CS) and the in 1943 and 1944 American Combined Chiefs of Staff (CCS) was handled with high security.

The successor to Rockex was the Noreen (BID / 590) from the early 1960s .

Louis Kruh: British Rockex Cipher Machines. Cryptologia , 11: 4, 1987, pp. 245-247, doi: 10.1080 / 0161-118791862072
Louis Kruh: British-American Cryptanalytic Cooperation and an Unprecendented Admission by Winston Churchill , Cryptologia, 13: 2, 1989, pp. 123-134, doi: 10.1080 / 0161-118991863835