Government Communications Headquarters: Communications-Electronic Security Group,...

HW 9

1944-1970

Records relating to the security of electronic communications since 1944. The initial transfer cover such topics as: - correspondence on communications security (COMSEC) matters - agendas/minutes of meetings covering communications security policy and organization, codes and cypher production methods, users, requirements, problems, costs - development of codes/cypher and speech secrecy systems and equipment - communications security assessments, equipment evaluation reports, research policy

Former reference order.

L file series

Public Record(s)

English

52 file(s)

Retained by department unless otherwise stated

In 1996-2017 Government Communications Headquarters

Topics

Research

Intelligence

No further accruals are expected.

Following the end of the Second World War communications security (COMSEC) was reviewed at the highest level. A new section covering all aspects of cypher security was constituted, initially entitled the Cypher Security Group but in 1946, under the reorganisation into GCHQ, it was changed to L (London) Group, and subsequently to L Division.

In 1954, much of the COMSEC aspect of GCHQ's responsibilities was transferred to a new department, independent of GCHQ, the London Communications Security Agency (LCSA), but L Division of GCHQ remained, and continued to be engaged on COMSEC tasks.

Also in 1954, the London Communications Security Board (LCSB) was established which superseded the CPB. The LCSB, assisted by a Committee, the London Communications Security Committee (LCSC), continues to function at present.

In 1965, the LCSA was reorganised into the Communications-Electronics Security Department (CESD) which was reintegrated into GCHQ as Communications-Electronics Security Group (CESG) in 1969 when it subsumed L Division and T Division (mainly technical). During the intervening period from 1954 to 1969, however, LCSA/CESD continued to have a very close relationship with GCHQ and L Division, which provided advice, cooperation and assistance in COMSEC matters and produced all code and cypher material for user departments.

Today, CESG is the national technical authority responsible to the LCSB for all information security (Infosec) matters where official information is communicated electronically. CESG is tasked with developing and promoting effective Infosec measures to meet any perceived threat. Its remit includes: assessment of the Sigint threat to and vulnerabilities of HMG communications, to include the security of related equipment, systems and procedures and the security of information technology (IT) networks; design and development of technical solutions to protect electronic communications; production of key material for use with approved communications systems.