Official Secrets Act

An Official Secrets Act (OSA) is legislation that provides for the protection of state secrets and official information, mainly related to national security but in unrevised form (based on the UK OSA 1911) can include all information held by government bodies. 
OSAs are currently in-force in over 40 countries (mostly former British colonies) including Bangladesh, Kenya, Pakistan, Hong Kong, India, Ireland, Myanmar, Uganda, Malaysia, Singapore and the United Kingdom, and have previously existed in Canada and New Zealand. 
There were earlier English and British precedents, long before the acts enumerated here. As early as the 16th Century, following Francis Drake's circumnavigation, Queen Elizabeth I declared that all written accounts of Drake's voyages were to become the 'Queen's secrets of the Realm'. In addition, Drake and the other participants of his voyages were sworn to their secrecy on the pain of death; the Queen intended to keep Drake's activities away from the eyes of rival Spain.
Countries and legislation.
United Kingdom.
People working with sensitive information are commonly required to sign a statement to the effect that they agree to abide by the restrictions of the Official Secrets Act. This is popularly referred to as "signing the Official Secrets Act". Signing this has no effect on which actions are legal, as the act is a law, not a contract, and individuals are bound by it whether or not they have signed the act. Signing it is intended more as a reminder to the person that they are under such obligations. To this end, it is common to sign this statement both before and after a period of employment that involves access to information classified as 'secret' (e.g. MI5/MI6).
Other legislation.
In addition to the Official Secrets Acts, the Naval Discipline Act 1957 made it an offence to spy on-board Royal Navy ships or overseas bases. It was punishable by life imprisonment. This was a capital offence until 1981.
Canada.
22 prosecutions occurred under the Official Secrets Act in Canada, over half of which were in relation to the Gouzenko Affair. In 1989, Stephen Joseph Ratkai was charged and convicted under the Act, of espionage in relation to the SOSUS network site at Naval Station Argentia in Newfoundland.
Official Secrets Acts in other countries.
The phrase "official secrets act" may also be used to refer to statutes of a similar nature in other countries. Canada's "Official Secrets Act" was replaced in 2001 by similar legislation titled the "Security of Information Act" (which was created in the wake of September 11th 2001 to replace the vaguely worded Official Secrets Act).
The United States does not have a broad-reaching Official Secrets Act, although the Espionage Act of 1917 has similar components. Much of the Espionage Act remains in force, although some has been struck down by the Supreme Court as unconstitutional because of the First Amendment (See "United States v. The Progressive", "Brandenburg v. Ohio", "New York Times Co. v. United States"). , enacted in 1951, makes dissemination of secret information involving cryptography, espionage, and surveillance illegal for all people, and is thus an "official secrets act" limited to those subjects.
In the Republic of Ireland the Official Secrets Act, 1963 repealed previous British legislation of 1911 and 1920. The Official Secrets Act, as amended, applies to all civil servants and potentially anyone within the state. A suit may only be instigated at the approval of the Attorney General of Ireland, additionally proceedings may occur in camera but the verdict and any sentence must occur in public.
Malaysia has an Official Secrets Act (also referred to as the OSA) prohibiting the collection, possession or distribution of information marked as an official secret—an action which can be made by any public officer. The certification of a document as an official secret is not subject to judicial review, and a violation of the act is punishable with between one and seven years' imprisonment. The act has been controversial for its use to silence dissent and stifling anti-corruption activities.
Australia previously had Part VII of the Crimes Act 1914 (Commonwealth), entitled "Official Secrets and Unlawful Soundings" (since repealed and replaced with Part 5.6 - Secrecy of Information of the Criminal Code Act (1995) ).