Government Code and Cypher School: Administration Files on the Radio Security Service

This series contains records of Government Code and Cypher School tasking of Radio Security Service for interception of German and other enemy illicit wireless communications, analysis of the communications, and records of relations with wartime allies on radio security matters. It includes the minutes of the Radio Security Intelligence Conferences.

The records in this series were retained by the department under s.3(4) of the Public Records Act 1958, until it was decided that they could be made available to the public. The records were open from the date of transfer to the PRO.

Messages intercepted by RSS were passed to Oliver Strachey's section at GCCS to be decoded and reported on. These reports are in HW 19

Radio Security Service files on Polish matters are in HW 47.

From 2001 Government Communications Headquarters

Topics

Radio and television

Intelligence

Communications

The Radio Security Service (RSS) was established in September 1939, following an investigation and report by Lord Hankey, with the responsibility for detection of illicit wireless communications within the UK and surrounding sea. Initially under the control of MI8 of the War Office, and using physical facilities provided by the Post Office, RSS supplied the Security Service with details of intercepted communications.

In May of 1940 RSS was made responsible for interception of German overseas illicit transmissions, and by the end of 1940 for the global interception of enemy secret service communications. In January 1941 RSS passed to the control of the Secret Intelligence Service (SIS), and in August of that year it assumed responsibility for the overseas interception units, previously under MI8 control. As well as targeting known enemy radio-communications networks, RSS undertook systematic searches and analysis of the radio spectrum looking for illicit broadcasts, which could then be targeted. These searches utilised home-based volunteer interceptors, who reported their findings by post to RSS.

At RSS headquarters in Barnet, the Radio Intelligence Section of RSS undertook intelligence analysis in co-operation with the Government Code and Cypher School (GC&CS) and the SIS, which resulted in regular Radio Security Intelligence conferences. RSS also had responsibility for monitoring allied non-military communications, mainly within the UK. In 1946, RSS was taken over by Government Communications Headquarters (formerly GC&CS).