Rockex, or Telekrypton, was an offline

one-time tape In cryptography, the one-time pad (OTP) is an encryption technique that cannot be cracked, but requires the use of a single-use pre-shared key that is not smaller than the message being sent. In this technique, a plaintext is paired with a ra ...

Vernam cipher machine known to have been used by

Britain Britain most often refers to: * The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands * Great Britain, the largest island in the United King ...

and

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

from 1943. It was developed by Canadian electrical engineer Benjamin deForest Bayly, working during the war for British Security Coordination. "Rockex" was named after the

Rockefeller Center Rockefeller Center is a large complex consisting of 19 commerce, commercial buildings covering between 48th Street (Manhattan), 48th Street and 51st Street (Manhattan), 51st Street in Midtown Manhattan, New York City. The 14 original Art Deco ...

,Louis Kruh, British intelligence in the Americas, ''Cryptologia'', April 2001 together with the tradition for naming British cipher equipment with the suffix "-ex" (e.g. Typex). In 1944 an improved Rockex II first appeared. There were also a Mark III and Mark V. After the war it was used by British consulates and embassies until 1973, although a few continued in use until the mid-1980s.Exhibit card describing Rockex equipment in the "Enigma and Friends" exhibit at the

Bletchley Park Bletchley Park is an English country house and estate in Bletchley, Milton Keynes (Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following ...

museum, September 2006 After WW2 the Rockex machines and the code tapes were manufactured in great secrecy under the control of the

Secret Intelligence Service The Secret Intelligence Service (SIS), commonly known as MI6 ( Military Intelligence, Section 6), is the foreign intelligence service of the United Kingdom, tasked mainly with the covert overseas collection and analysis of human intellige ...

(SIS), also known as MI6, at a small factory at Number 4 Chester Road, Borehamwood on the northern outskirts of London. To minimise the number of people who knew about the process, MI6's head of communications, Brigadier Sir Richard Gambier-Parry, took out a personal lease on the factory buildings and employed people through the local labour exchange as an entirely private venture ostensibly unconnected with government. The end product was then sold to the government departments who used the machines. This was not discovered by the UK Treasury until 1951 who were most concerned that no form of financial auditing had ever been exercised over the organisation. The Treasury officials were eventually convinced that the factory needed to be treated as a special case and they allowed it to continue privately but with a special arrangement for top secret auditing (Natl Archives file T220/1444)

References

External links

Jerry Proc's page on Rockex

Rockex on Crypto Museum website
*

5-UCO The 5-UCO (5-Unit Controlled)Ralph Erskine, "The 1944 Naval BRUSA Agreement and its Aftermath", ''Cryptologia'' 30(1), January 2006 pp14–15 was an on-line one-time tape Vernam cipher encryption system developed by the UK during World War II f ...

References

External links

See also