Editing Ultra (cryptography) (section)

==Distribution==
[[File:Ultra Hut3 Graph.png|thumb|upright=1.5|Average numbers of daily Ultra dispatches to field commanders during World War II{{sfn|Bennett|1999|p=302}}]]
Army- and Air Force-related intelligence derived from [[signals intelligence]] (SIGINT) sources{{snd}}mainly Enigma decrypts in [[Hut 6]]{{snd}}was compiled in summaries at GC&CS ([[Bletchley Park]]) Hut 3 and distributed initially under the codeword "BONIFACE",{{sfn|West|1986|p=136}} implying that it was acquired from a well placed agent in Berlin. The volume of the intelligence reports going out to commanders in the field built up gradually.

Naval Enigma decrypted in [[Hut 8]] was forwarded from Hut 4 to the [[British Admiralty|Admiralty]]'s Operational Intelligence Centre (OIC),{{sfn|Beesly|1977|p=36}} which distributed it initially under the codeword "HYDRO".{{sfn|West|1986|p=136}}

The codeword "ULTRA" was adopted in June 1941.{{sfn|West|1986|p=162}} This codeword was reportedly suggested by Commander Geoffrey Colpoys, RN, who served in the Royal Navy's OIC.

===Army and Air Force===
The distribution of Ultra information to Allied commanders and units in the field involved considerable risk of discovery by the Germans, and great care was taken to control both the information and knowledge of how it was obtained. Liaison officers were appointed for each field command to manage and control dissemination.

Dissemination of Ultra intelligence to field commanders was carried out by [[MI6]], which operated [[Special Liaison Units]] (SLU) attached to major army and air force commands. The activity was organized and supervised on behalf of MI6 by [[Group captain|Group Captain]] [[F. W. Winterbotham]]. Each SLU included intelligence, communications, and cryptographic elements. It was headed by a British Army or RAF officer, usually a major, known as "Special Liaison Officer". The main function of the liaison officer or his deputy was to pass Ultra intelligence bulletins to the commander of the command he was attached to, or to other indoctrinated staff officers. In order to safeguard Ultra, special precautions were taken. The standard procedure was for the liaison officer to present the intelligence summary to the recipient, stay with him while he studied it, then take it back and destroy it.

By the end of the war, there were about 40 SLUs serving commands around the world.{{sfn|Calvocoressi|2001|pp=78}} Fixed SLUs existed at the Admiralty, the [[War Office]], the [[Air Ministry]], [[RAF Fighter Command]], the US Strategic Air Forces in Europe (Wycombe Abbey) and other fixed headquarters in the UK. An SLU was operating at the War HQ in Valletta, Malta.{{sfn|Stephenson|2004|p=56}} These units had permanent teleprinter links to Bletchley Park.

Mobile SLUs were attached to field army and air force headquarters and depended on radio communications to receive intelligence summaries. The first mobile SLUs appeared during the French campaign of 1940. An SLU supported the [[British Expeditionary Force (World War II)|British Expeditionary Force]] (BEF) headed by [[John Vereker, 6th Viscount Gort|General Lord Gort]]. The first liaison officers were Robert Gore-Browne and Humphrey Plowden.{{sfn|West|1986|p=138}} A second SLU of the 1940 period was attached to the [[RAF Advanced Air Striking Force]] at [[Meaux]] commanded by Air Vice-Marshal [[Patrick Playfair|P H Lyon Playfair]]. This SLU was commanded by Squadron Leader F.W. "Tubby" Long.

===Intelligence agencies===
In 1940, special arrangements were made within the British intelligence services for handling BONIFACE and later Ultra intelligence. The [[MI5|Security Service]] started "Special Research Unit B1(b)" under [[H. L. A. Hart|Herbert Hart]]. In the [[MI6|SIS]] this intelligence was handled by "Section V" based at [[St Albans]].{{sfn|West|1986|p=152}}

===Radio and cryptography===
The communications system was founded by Brigadier Sir [[Richard Gambier-Parry]], who from 1938 to 1946 was head of MI6 Section VIII, based at [[Whaddon Hall]] in [[Buckinghamshire]], UK.{{sfn|Pidgeon|2003}} Ultra summaries from Bletchley Park were sent over landline to the Section VIII radio transmitter at Windy Ridge. From there they were transmitted to the destination SLUs.

The communications element of each SLU was called a "Special Communications Unit" or SCU. Radio transmitters were constructed at Whaddon Hall workshops, while receivers were the [[National HRO]], made in the USA. The SCUs were highly mobile and the first such units used civilian [[Packard]] cars. The following SCUs are listed:{{sfn|Pidgeon|2003}} SCU1 (Whaddon Hall), SCU2 (France before 1940, India), SCU3 (RSS Hanslope Park), SCU5, SCU6 (possibly Algiers and Italy), SCU7 (training unit in the UK), SCU8 (Europe after D-day), SCU9 (Europe after D-day), SCU11 (Palestine and India), SCU12 (India), SCU13 and SCU14.{{efn|In addition, there were SCU3 and SCU4, which supported ''Y Service'' radio intercepting and direction finding facilities. These units were formed from assets of the former [[MI8|Radio Security Service]], after it was reassigned to MI6 and they were not involved in Ultra dissemination.}}

The cryptographic element of each SLU was supplied by the RAF and was based on the [[Typex|TYPEX]] cryptographic machine and [[one-time pad]] systems.

RN Ultra messages from the OIC to ships at sea were necessarily transmitted over normal naval radio circuits and were protected by one-time pad encryption.{{sfn|Beesly|1977|p=142}}

===Lucy===
It is alleged that Ultra information was used by the [[Lucy spy ring|"Lucy" spy ring]],<ref>{{cite news| url=https://www.latimes.com/archives/la-xpm-1987-08-09-bk-198-story.html | title=Operation 'Citadel'—Kursk and Orel: The Greatest Tank Battle of the Second World War by Janusz Piekalkiewicz; translated by Michaela Nierhaus; (Presidio: $25; 288 pp., illustrated) |type=book review | first=Janusz |last=Piekalkiewicz | date=9 August 1987 | newspaper=Los Angeles Times| access-date=8 June 2016}}</ref> headquartered in [[Switzerland]] and apparently operated by one man, [[Rudolf Roessler]]. This was an extremely well informed, responsive ring that was able to get information "directly from German General Staff Headquarters"{{snd}}often on specific request. It has been alleged that "Lucy" was in major part a conduit for the British to feed Ultra intelligence to the Soviets in a way that made it appear to have come from highly placed espionage rather than from [[cryptanalysis]] of German radio traffic. The Soviets, however, through an agent at Bletchley, [[John Cairncross]], knew that Britain had broken Enigma. The "Lucy" ring was initially treated with suspicion by the Soviets. The information it provided was accurate and timely, however, and Soviet agents in Switzerland (including their chief, [[Alexander Radó]]) eventually learned to take it seriously.{{sfn|Crowdy|2011|pp=307–309}} However, the theory that the Lucy ring was a cover for Britain to pass Enigma intelligence to the Soviets has not gained traction. Among others who have rejected the theory, [[Harry Hinsley]], the official historian for the British Secret Services in World War II, stated that "there is no truth in the much-publicized claim that the British authorities made use of the ‘Lucy’ ring&nbsp;... to forward intelligence to Moscow".{{sfn|Tarrant|1995|p=170}}