I’m studying the use of wireless interception in World War Two. In particular, The Raddio Security Service in U.K. their product was given the codename ISOS and was part of the ULTRA intelligence from Bletchley Park. The intelligence was shared with USA as part of the BRUSA agreement.

The government records on the organisation have not been released by MI6, the Secret Intelligence Service, who have never released any of their files to the U.K. national archives. It’s therefore necessary to find evidence from other WW2 intelligence organisations that may have received information from MI6 or GCHQ (then called Government code and cypher school).

The main target for RSS interception was the German intelligence services the Abwehr and the Sicherheitsdeinst. Ant the secret intelligence services of Italy, Japan and other countries involved with Germany.