Australia's electronic espionage agency is a partner in a massive United States-led assault on internet security and privacy, according to top secret documents disclosed by former US intelligence contractor Edward Snowden.

The German Der Spiegel magazine has published new disclosures of signals intelligence cooperation between the United States and its "5-eyes" partners – the United Kingdom, Canada, Australia and New Zealand – revealing that the secret agencies have broken most widely-used forms of internet encryption.

The NSA has been cracking encryption for years. Credit:Reuters

Many of the leaked documents are classified top secret, "COMINT" (communications intelligence) and releasable only to "5-eyes" agencies – the US National Security Agency (NSA), the Australian Signals Directorate (ASD), the United Kingdom's Government Communications Headquarters, Canada's Communications Security Establishment and New Zealand's Government Communications Security Bureau.

Intensive efforts to overcome what is described as the "major threat" of "ubiquitous encryption" on the internet have been regularly discussed at top secret "SIGDEV" – signals intelligence development conferences between the "5-eyes" agencies.