The mandate of the Government Communications Security Bureau [GCSB] is to satisfy the foreign intelligence requirements of the NZ Government. The focus of its intelligence activities is restricted to foreign intelligence. GCSB collects, assesses, produces reports and disseminates foreign intelligence to meet the national foreign intelligence requirements of the New Zealand Government and its agencies. It also has subsidiary functions which assist its collection capability by signals research identification and analysis of signal sources and devices.
Collection is made from electronic communication transmitted through satellite, radio waves or other open means. GCSB does not intercept private or other communication transmitted by telephone land lines. GCSB operates a satellite monitoring station at Waihopai near Blenheim and a radio receiving station at Tangimoana near Foxton. These are both capable of receiving and collecting foreign intelligence. The equipment is equally capable of receiving signals transmitted by radio and satellite which do not include foreign intelligence and which are domestic concerning and involving NZ citizens.
Government initiatives announced in 1997 to enhance the foreign signals intelligence collection capability of the GCSB include constructing a second antenna at Waihopai and to extend the authority of the GCSB to collect foreign voice communications. The latter was attended to by the making of the Crimes (Exemption of Listening Device) Order 1997. That exempted the GCSB's station at Waihopai from the provisions of Part IX.A of the Crimes Act 1961 for the purpose only of intercepting foreign voice communications containing foreign intelligence.
Through the UK-USA agreements, GCSB has links with the National Security Agency US, Communications Security Establishment Canada, Defence Signals Directorate Australia and the Government Communications Headquarters United Kingdom.