The two main tasks of FRA are signals intelligence (SIGINT), and support to government authorities and state-owned companies regarding computer security.

After two weeks of single hand work, the Swedish professor of mathematics Arne Beurling, decoded the cipher of the Geheimfernschreiber with only use of pencil and paper.

This achievement was described by David Kahn, in his book The Codebreakers: "Quite possibly the finest feat of cryptanalysis performed during the Second World War was Arne Beurling's solution of the secret of the G-schreiber."

For Finland, it resulted in a domestic political affair and due to the Communist Party's strong influence in the government, several of the so-called "Soviet Hostiles" involved received prison sentences.

The Swedish government initially claimed that the flight was only a navigational exercise, but later admitted that the aeroplane had U.S. electronic surveillance equipment and five specialists from FRA on board.

Three days later, a Swedish Air Force search-and-rescue plane of the type Tp 47 (Catalina) was shot down by a Soviet MiG-15 fighter, but the crew was rescued by a nearby West German freighter ship.

[17][18] The FRA has a long history of intercepting radio signals, as the main intelligence agency producing and managing SIGINT in Sweden since 1942.

[21] As an ever-increasing amount of communications have transferred from radio to cables, the question of enabling FRA to collect information from cable communication was addressed by Göran Persson's cabinet in a government appointed committee of inquiry led by General Owe Wiktorin in 2003, resulting in a report suggesting a change in legislation (SOU 2003:30).

[23] These changes would have allowed the FRA to monitor both wireless and cable bound signals passing the Swedish border without a court order,[24] while also introducing several provisions designed to protect the privacy of individuals, according to the original proposal.

[23] The law's proponents argued for the need to give FRA new guidelines and a modernised legal framework, in order to regulate Internet surveillance and to combat threats to national security more effectively, such as terrorism and serious transnational crime; while opponents to the law claimed it enabled mass surveillance and violated privacy rights.

[24][25][26] Criticised for being too far-reaching, in an attempt to address the privacy concerns raised during the parliamentary procedure,[27] the Government soon thereafter proposed an amendment to the law (Prop.

[22] According to the law (SFS 2008:717), SIGINT is only permitted in order to assess:[29][31] The FRA is not allowed to initialize any surveillance on their own,[8] and only gets access to communication lines as decided by The Defence Intelligence Court.

[43] In 2008, prior to the change in legislation, a news report from SVT, based on an account from an anonymous source, alleged the FRA had been storing personal information for much longer;[44] leading to a private citizen lodging a complaint with the police.

[29] The decisions of the court cannot be appealed, something that is motivated, in part, by information sensitivity and the fact that special knowledge and physical protection of infrastructure and documents is needed.

[...] The marginal benefits to be gained with a right of appeal by the special ombudsman can equally well be achieved with high-quality court members and delegates.

In December 2010, after a two-year-long audit, a special mission led by the board examining FRA concluded its operations are within bounds of applicable legislation.

[57][58] In return, Sweden could receive information of importance to the national interest, something the Director-General of FRA Ingvar Åkesson and the Minister for Foreign Affairs Carl Bildt both stressed when the legislation was debated in 2008.

[22][69] Anni Bölenius, head of communications at the FRA, believes the public perception of mass surveillance is incorrect, saying: "It is not as we can turn on the traffic ourselves.

[22] The court also hear each case on an individual basis, something Minister for Defence Sten Tolgfors have been quoted as saying, "should render the debate on mass surveillance invalid.